the root thesis

thesis (n.)

late 14c., "unaccented syllable or note, a lowering of the voice in music," from Latin thesis "unaccented syllable in poetry," later (and more correctly) "stressed part of a metrical foot," from Greek thesis "a proposition," also "downbeat" (in music), originally "a setting down, a placing, an arranging; position, situation" (from reduplicated form of PIE root *dhe- "to set, put").

The sense in logic of "a formulation in advance of a proposition to be proved or debated" is attested by 1570s (contrasted to hypothesis ; in rhetoric it is opposed to antithesis ); that of "dissertation presented by a candidate for a university degree" is from 1650s. The uncertainty of the prosodic sense might have kept it from being established in English. Related: Thetic ; thetical ; thetically .

Entries linking to thesis

*dhē- , Proto-Indo-European root meaning "to set, put."

It forms all or part of: abdomen ; abscond ; affair ; affect (v.1) "make a mental impression on;" affect (v.2) "make a pretense of;" affection ; amplify ; anathema ; antithesis ; apothecary ; artifact ; artifice ; beatific ; benefice ; beneficence ; beneficial ; benefit ; bibliothec ; bodega ; boutique ; certify ; chafe ; chauffeur ; comfit ; condiment ; confection ; confetti ; counterfeit ; deed ; deem ; deface ; defeasance ; defeat ; defect ; deficient ; difficulty ; dignify ; discomfit ; do (v.); doom ; -dom ; duma ; edifice ; edify ; efface ; effect ; efficacious ; efficient ; epithet ; facade ; face ; facet ; facial ; -facient ; facile ; facilitate ; facsimile ; fact ; faction (n.1) "political party;" -faction ; factitious ; factitive ; factor ; factory ; factotum ; faculty ; fashion ; feasible ; feat ; feature ; feckless ; fetish ; -fic ; fordo ; forfeit ; -fy ; gratify ; hacienda ; hypothecate ; hypothesis ; incondite ; indeed ; infect ; justify ; malefactor ; malfeasance ; manufacture ; metathesis ; misfeasance ; modify ; mollify ; multifarious ; notify ; nullify ; office ; officinal ; omnifarious ; orifice ; parenthesis ; perfect ; petrify ; pluperfect ; pontifex ; prefect ; prima facie ; proficient ; profit ; prosthesis ; prothesis ; purdah ; putrefy ; qualify ; rarefy ; recondite ; rectify ; refectory ; sacrifice ; salmagundi ; samadhi ; satisfy ; sconce ; suffice ; sufficient ; surface ; surfeit ; synthesis ; tay ; ticking (n.); theco- ; thematic ; theme ; thesis ; verify .

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dadhati "puts, places;" Avestan dadaiti "he puts;" Old Persian ada "he made;" Hittite dai- "to place;" Greek tithenai "to put, set, place;" Latin facere "to make, do; perform; bring about;" Lithuanian dėti "to put;" Polish dziać się "to be happening;" Russian delat' "to do;" Old High German tuon , German tun , Old English don "to do."

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Definition of thesis

Did you know.

In high school, college, or graduate school, students often have to write a thesis on a topic in their major field of study. In many fields, a final thesis is the biggest challenge involved in getting a master's degree, and the same is true for students studying for a Ph.D. (a Ph.D. thesis is often called a dissertation ). But a thesis may also be an idea; so in the course of the paper the student may put forth several theses (notice the plural form) and attempt to prove them.

Examples of thesis in a Sentence

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'thesis.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

in sense 3, Middle English, lowering of the voice, from Late Latin & Greek; Late Latin, from Greek, downbeat, more important part of a foot, literally, act of laying down; in other senses, Latin, from Greek, literally, act of laying down, from tithenai to put, lay down — more at do

14th century, in the meaning defined at sense 3a(1)

Dictionary Entries Near thesis

the sins of the fathers are visited upon the children

thesis novel

Cite this Entry

“Thesis.” Merriam-Webster.com Dictionary , Merriam-Webster, https://www.merriam-webster.com/dictionary/thesis. Accessed 23 May. 2024.

Kids Definition

Kids definition of thesis, more from merriam-webster on thesis.

Nglish: Translation of thesis for Spanish Speakers

Britannica English: Translation of thesis for Arabic Speakers

Britannica.com: Encyclopedia article about thesis

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• 1.1 Etymology
• 1.2 Pronunciation
• 1.3.1 Derived terms
• 1.3.2 Related terms
• 1.3.3 Translations
• 1.4 References
• 1.5 Further reading
• 1.6 Anagrams
• 2.1 Etymology
• 2.2 Pronunciation
• 3.1 Etymology
• 3.2 Pronunciation
• 3.3.1 Declension
• 3.3.2 Descendants
• 3.4 References

English [ edit ]

Etymology [ edit ].

From Late Middle English thesis ( “ lowering of the voice ” ) [1] and also borrowed directly from its etymon Latin thesis ( “ proposition, thesis; lowering of the voice ” ) , from Ancient Greek θέσῐς ( thésis , “ arrangement, placement, setting; conclusion, position, thesis; lowering of the voice ” ) , from τῐ́θημῐ ( títhēmi , “ to place, put, set; to put down in writing; to consider as, regard ” ) [2] [3] (ultimately from Proto-Indo-European *dʰeh₁- ( “ to do; to place, put ” ) ) + -σῐς ( -sis , suffix forming abstract nouns or nouns of action, process, or result ) . The English word is a doublet of deed .

Sense 1.1 (“proposition or statement supported by arguments”) is adopted from antithesis . [2] Sense 1.4 (“initial stage of reasoning”) was first used by the German philosopher Johann Gottlieb Fichte (1762–1814), and later applied to the dialectical method of his countryman, the philosopher Georg Wilhelm Friedrich Hegel (1770–1831).

The plural form theses is borrowed from Latin thesēs , from Ancient Greek θέσεις ( théseis ) .

Pronunciation [ edit ]

• ( Received Pronunciation ) IPA ( key ) : /ˈθiːsɪs/ , ( archaic ) /ˈθɛsɪs/
• ( General American ) IPA ( key ) : /ˈθisɪs/
• Rhymes: -iːsɪs
• Hyphenation: the‧sis
• ( Received Pronunciation ) IPA ( key ) : /ˈθiːsiːz/
• ( General American ) IPA ( key ) : /ˈθisiz/
• Rhymes: -iːsiːz
• Hyphenation: the‧ses

Noun [ edit ]

thesis ( plural theses )

• ( rhetoric ) A proposition or statement supported by arguments .
• 1766 , [ Oliver Goldsmith ], “The Conclusion”, in The Vicar of Wakefield:   [ … ] , volume II, Salisbury, Wiltshire: [ … ] B. Collins, for F [ rancis ] Newbery ,   [ … ] , →OCLC ; reprinted London: Elliot Stock , 1885 , →OCLC , pages 218–219 : I told them of the grave, becoming, and ſublime deportment they ſhould aſſume upon this myſtical occaſion, and read them two homilies and a theſis of my own compoſing, in order to prepare them.
• ( mathematics , computer science ) A conjecture , especially one too vague to be formally stated or verified but useful as a working convention.
• ( logic ) An affirmation , or distinction from a supposition or hypothesis .
• ( philosophy ) In the dialectical method of Georg Wilhelm Friedrich Hegel : the initial stage of reasoning where a formal statement of a point is developed ; this is followed by antithesis and synthesis .
• ( music , prosody , originally ) The action of lowering the hand or bringing down the foot when indicating a rhythm ; hence, an accented part of a measure of music or verse indicated by this action; an ictus , a stress . Antonym: arsis
• ( music , prosody , with a reversal of meaning ) A depression of the voice when pronouncing a syllables of a word ; hence, the unstressed part of the metrical foot of a verse upon which such a depression falls , or an unaccented musical note .

Derived terms [ edit ]

• all but thesis
• bachelor's thesis
• Church-Turing thesis
• conflict thesis
• doctoral thesis
• graduate thesis
• Habakkuk thesis
• master's thesis
• Merton thesis
• private language thesis
• thesis defense
• thesis film
• thesis statement

Related terms [ edit ]

Translations [ edit ], references [ edit ].

• ^ “ thē̆sis, n. ”, in MED Online , Ann Arbor, Mich.: University of Michigan , 2007 .
• ^ “ thesis, n. ”, in Lexico , Dictionary.com ; Oxford University Press , 2019–2022 .

Further reading [ edit ]

• “ thesis ”, in The Century Dictionary   [ … ] , New York, N.Y.: The Century Co. , 1911 , →OCLC .
• “ thesis ”, in Webster’s Revised Unabridged Dictionary , Springfield, Mass.: G. & C. Merriam , 1913 , →OCLC .

Anagrams [ edit ]

• Heists , Sethis , heists , shiest , shites , sithes , thises

Dutch [ edit ]

From Latin thesis , from Ancient Greek θέσις ( thésis , “ a proposition, a statement, a thing laid down, thesis in rhetoric, thesis in prosody ” ) .

thesis   f ( plural theses or thesissen , diminutive thesisje   n )

• Dated form of these . Synonyms: dissertatie , proefschrift , scriptie

Latin [ edit ]

From Ancient Greek θέσις ( thésis , “ a proposition, a statement, a thing laid down, thesis in rhetoric, thesis in prosody ” ) .

• ( Classical ) IPA ( key ) : /ˈtʰe.sis/ , [ˈt̪ʰɛs̠ɪs̠]
• ( modern Italianate Ecclesiastical ) IPA ( key ) : /ˈte.sis/ , [ˈt̪ɛːs̬is]

thesis   f ( genitive thesis ) ; third declension

Declension [ edit ]

Descendants [ edit ].

• → Dutch: thesis
• → Armenian: թեզ ( tʻez )
• → Dutch: these
• → Persian: تز ( tez )
• → Romanian: teză
• → Turkish: tez
• Galician: tese
• Italian: tesi
• English: thesis
• Portuguese: tese
• Spanish: tesis
• “ thesis ”, in Charlton T. Lewis and Charles Short ( 1879 ) A Latin Dictionary , Oxford: Clarendon Press
• thesis in Gaffiot, Félix ( 1934 ) Dictionnaire illustré latin-français , Hachette.

• English terms derived from Proto-Indo-European
• English terms derived from the Proto-Indo-European root *dʰeh₁-
• English terms inherited from Middle English
• English terms derived from Middle English
• English terms borrowed from Latin
• English terms derived from Latin
• English terms derived from Ancient Greek
• English doublets
• English 2-syllable words
• English terms with IPA pronunciation
• English terms with audio links
• Rhymes:English/iːsɪs
• Rhymes:English/iːsɪs/2 syllables
• Rhymes:English/iːsiːz
• English lemmas
• English nouns
• English countable nouns
• English nouns with irregular plurals
• en:Rhetoric
• English terms with quotations
• en:Mathematics
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• Dutch nouns
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• Dutch nouns with plural in -en
• Dutch feminine nouns
• Dutch dated forms
• Latin terms derived from Proto-Indo-European
• Latin terms derived from the Proto-Indo-European root *dʰeh₁-
• Latin terms borrowed from Ancient Greek
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• Latin 2-syllable words
• Latin terms with IPA pronunciation
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[ thee -sis ]

He vigorously defended his thesis on the causes of war.

Synonyms: proposal , contention , theory

• a subject for a composition or essay.
• a dissertation on a particular subject in which one has done original research, as one presented by a candidate for a diploma or degree.
• Music. the downward stroke in conducting; downbeat. Compare arsis ( def 1 ) .
• a part of a metrical foot that does not bear the ictus or stress.
• (less commonly) the part of a metrical foot that bears the ictus. Compare arsis ( def 2 ) .
• Philosophy. Hegelian dialectic

/ ˈθiːsɪs /

• a dissertation resulting from original research, esp when submitted by a candidate for a degree or diploma
• a doctrine maintained or promoted in argument
• a subject for a discussion or essay
• an unproved statement, esp one put forward as a premise in an argument
• music the downbeat of a bar, as indicated in conducting
• (in classical prosody) the syllable or part of a metrical foot not receiving the ictus Compare arsis
• philosophy the first stage in the Hegelian dialectic, that is challenged by the antithesis
• The central idea in a piece of writing, sometimes contained in a topic sentence .

Discover More

Word history and origins.

Origin of thesis 1

Example Sentences

“The Saudis have been proving the thesis of the film — they do in fact have an army,” said Thor Halvorssen, founder and chief executive of the nonprofit Human Rights Foundation, which funded the movie.

It’s a hypothesis that Bush pursued in her master’s thesis, and last year she began attending virtual Goth parties in a final round of field work before defending her doctoral thesis later this year.

While this partnership was planned prior to the coronavirus outbreak, co-founder Jordana Kier said the pandemic instantly proved out the expansion thesis.

They’ve had to defend that thesis for a very, very long time in front of a variety of different customers and different people.

Over the past decade, In-Q-Tel has been one of the most active investors in the commercial space sector, with a broad investment thesis that touches many aspects of the sector.

In “Back Home,” Gil also revisits the nostalgia for the South explored in his Johns Hopkins thesis, “Circle of Stone.”

At least father and son were in alignment on this central thesis: acting “gay”—bad; being thought of as gay—bad.

Her doctoral thesis, says Ramin Takloo at the University of Illinois, was simply outstanding.

Marshall McLuhan long ago argued the now accepted thesis that different mediums have different influences on thinking.

He wrote his Master's thesis on the underrepresentation of young people in Congress.

And indeed for most young men a college thesis is but an exercise for sharpening the wits, rarely dangerous in its later effects.

It will be for the reader to determine whether the main thesis of the book has gained or lost by the new evidence.

But the word thesis, when applied to Systems, does not mean the 'position' of single notes, but of groups of notes.

This conclusion, it need hardly be said, is in entire agreement with the main thesis of the preceding pages.

Sundry outlying Indians, with ammunition to waste, took belly and knee rests and strengthened the thesis to the contrary.

Related Words

• proposition
• supposition

What Is The Plural Of Thesis?

Plural word for  thesis.

The plural form of thesis is theses , pronounced [ thee -seez ]. The plurals of several other singular words that end in -is are also formed in this way, including hypothesis / hypotheses , crisis / crises , and axis / axes . A similar change is made when pluralizing appendix as appendices . 

Irregular plurals that are formed like theses derive directly from their original pluralization in Latin and Greek.

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Definition of thesis noun from the Oxford Advanced Learner's Dictionary

• Students must submit a thesis on an agreed subject within four years.
• He presented this thesis for his PhD.
• a thesis for a master's degree
• He's doing a doctoral thesis on the early works of Shostakovich.
• Many departments require their students to do a thesis defense.
• She completed an MSc by thesis.
• her thesis adviser at MIT
• in a/​the thesis
• thesis about

Questions about grammar and vocabulary?

Find the answers with Practical English Usage online, your indispensable guide to problems in English.

• The basic thesis of the book is fairly simple.
• These latest findings support the thesis that sexuality is determined by nature rather than choice.
• formulate/​advance a theory/​hypothesis
• build/​construct/​create/​develop a simple/​theoretical/​mathematical model
• develop/​establish/​provide/​use a theoretical/​conceptual framework
• advance/​argue/​develop the thesis that…
• explore an idea/​a concept/​a hypothesis
• make a prediction/​an inference
• base a prediction/​your calculations on something
• investigate/​evaluate/​accept/​challenge/​reject a theory/​hypothesis/​model
• design an experiment/​a questionnaire/​a study/​a test
• do research/​an experiment/​an analysis
• make observations/​measurements/​calculations
• carry out/​conduct/​perform an experiment/​a test/​a longitudinal study/​observations/​clinical trials
• run an experiment/​a simulation/​clinical trials
• repeat an experiment/​a test/​an analysis
• replicate a study/​the results/​the findings
• observe/​study/​examine/​investigate/​assess a pattern/​a process/​a behaviour
• fund/​support the research/​project/​study
• seek/​provide/​get/​secure funding for research
• collect/​gather/​extract data/​information
• yield data/​evidence/​similar findings/​the same results
• analyse/​examine the data/​soil samples/​a specimen
• consider/​compare/​interpret the results/​findings
• fit the data/​model
• confirm/​support/​verify a prediction/​a hypothesis/​the results/​the findings
• prove a conjecture/​hypothesis/​theorem
• draw/​make/​reach the same conclusions
• read/​review the records/​literature
• describe/​report an experiment/​a study
• present/​publish/​summarize the results/​findings
• present/​publish/​read/​review/​cite a paper in a scientific journal
• The results of the experiment support his central thesis.
• Most people rejected this thesis at the time because it presumed evolution rather than creation.
• fundamental

Nearby words

• Cambridge Dictionary +Plus

Meaning of thesis in English

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• I wrote my thesis on literacy strategies for boys .
• Her main thesis is that children need a lot of verbal stimulation .
• boilerplate
• composition
• dissertation
• essay question
• peer review

You can also find related words, phrases, and synonyms in the topics:

thesis | Intermediate English

Examples of thesis, collocations with thesis.

These are words often used in combination with thesis .

Click on a collocation to see more examples of it.

Translations of thesis

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Word of the Day

an occasion when a driver in a motor race stops in the pits (= area where cars are repaired)

Apples and oranges (Talking about differences, Part 2)

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hypothetical

Something that is hypothetical is based on possible situations or events rather than actual ones.

The anti thes is of something is its opposite.

An epithet is a short description or term that usually follows and augments someone's name, such as the word "great" in "Alfred the Great."

parenthetical

A parenthetical remark further explains or qualifies information.

A syn thes is is the combination or blend of two or more things to form a new whole.

A thes is is a main idea for a paper that its author tries to prove by giving examples that support the idea.

antithetical

sharply contrasted in character or purpose

a proposal intended to explain certain facts or observations

hypothesize

to believe especially on uncertain or tentative grounds

parentheses

either of two punctuation marks (or) used to enclose textual material

parenthesis

Photosynthesis.

syn thes is of compounds with the aid of radiant energy (especially in plants)

combine so as to form a more complex, product

not of natural origin

a book containing a classified list of synonyms

an unproved statement put forward as a premise in an argument

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the-; them-, themat-, thes-, thet-

(latin: placing, setting; to place, to put).

• Table of Contents

Reason: The publisher demands no Open Access

until file(s) become available

THE ROLE OF BACTERIAL ROOT ENDOPHYTES IN TOMATO GROWTH AND DEVELOPMENT

Plant roots form an intimate relationship with a diversity of soil microorganisms. Some soil-borne microbes cause harmful diseases on crops, but others promote plant growth and enhance host resilience against stressors. Beneficial bacteria have a high potential as a strategy for sustainable agricultural management, many of which have been recognized and commercialized for improving crop growth. Unfortunately, field inoculants of beneficial bacteria often give inconsistent results due to various environmental factors hindering their beneficial properties. Improving crop production utilizing beneficial bacteria requires two approaches: 1) breeding for crops with the enhanced association for beneficial bacteria and 2) improving formulation methods for producing more potent microbial products. To contribute to these goals, we address three critical questions utilizing the tomato root microbiome as a model system. First, we asked how beneficial root-associated bacteria could be efficiently identified. We developed a strategy to select beneficial bacteria from a novel collection of 183 bacterial endophytes isolated from roots of two field-grown tomato species. The results suggest that isolates with similar traits impact plant growth at the same levels, regardless of their taxonomic classification or host origin. Next, we asked whether host genetics contribute to the root microbiome assembly and response to beneficial microbes. An assessment of the root microbiome profile and plant binary interaction experiments suggested the role of host genetics in influencing root recruitment and response to beneficial bacteria. Subsequently, we asked whether root-associated bacteria induce physiological changes in root tissues in the host. We identified two isolates from our bacterial endophyte collection that significantly promoted the growth of tomato genotype H7996 ( Solanum lycopersicum ). Plant-binary interaction experiments suggested a significant increase of cell wall lignification in the root vasculature starting 96-hour post-inoculation with beneficial bacteria. Additional studies are needed to uncover a possible correlation between the induced vasculature lignification and the growth-promoting effects of the two isolates on H7996. Altogether, our findings highlight the multi-faceted role of root-associated bacteria in promoting plant growth and support the development of crop improvement strategies in optimizing host association with soil bacteria.

Degree Type

• Doctor of Philosophy
• Botany and Plant Pathology

Campus location

• West Lafayette

Advisor/Supervisor/Committee Chair

Advisor/supervisor/committee co-chair, additional committee member 2, additional committee member 3, usage metrics.

• Plant pathology
• Microbial ecology
• Horticultural crop protection (incl. pests, diseases and weeds)

Advanced filters

Words that contain thesis.

• anaesthesis
• antimetathesis
• biosynthesis
• cenesthesis
• chemosynthesis
• coenaesthesis
• coenesthesis
• counterhypothesis
• hypothesise
• hypothesised
• hypothesiser
• hypothesisers
• hypothesises
• hypothesising
• hypothesist
• hypothesists
• kinaesthesis
• kinesthesis
• metathesise
• metathesised
• metathesises
• metathesising
• narcosynthesis
• nucleosynthesis
• parasynthesis
• parenthesis
• parenthesise
• parenthesised
• parenthesises
• parenthesising
• photosynthesis
• photosynthesise
• polysynthesis
• polysynthesism
• polysynthesisms
• psychosynthesis
• radiesthesist
• radiesthesists
• resynthesis
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These Researchers Are Digging Into the Understudied Science of Roots

P icture a plant—your favorite flower, an herb from an outdoor garden or a stately tree. As you visualize the elements of the flora, did you remember to include the roots? If you didn’t, you’re in good company.

“Roots definitely are central to plant systems, but when it comes to attention and studies in plant biology, the focus has mainly been on above-ground shoots, leaf tissues and photosynthesis,” says Amir Ahkami , a biologist at the Department of Energy’s Pacific Northwest National Laboratory.

Roots are typically at least half of a plant’s biomass , but you wouldn’t know it given how little scientific research has been devoted to these critical tendrils. Only recently have scientists given plant roots their day in the sun—in fields like collections research, climate science and microbiology. Historically, the reasons for this discrepancy were laughably simple: Studying something you have to dig up isn’t that easy.

Still, scientists hundreds of years ago managed to study these elusive subjects with ingenious methods. As early as the 19th century, botanist Julius von Sachs grew plants in a glass-sided root box to study their root systems in situ . His contemporaries—biologists Edward Janczewski, Sydney Howard Vines and Wilhelm Pfeffer—all made important advances in our understanding of root growth, development and osmosis, respectively. Yet, specialization in the intervening centuries siloed root science from the rest of botany, prompting the authors of a major root textbook to subtitle their work “The Hidden Half.” But now a scientific renaissance for root systems has been fueled by a combination of technological advances and a striking realization: Roots, we now know, can help us track our changing world, shape food security and model our future.

Digging back into the history of root science

For centuries, collections specialists would have looked at the dirty roots of specimens and considered them to be, at best, contamination. To these specialists, in charge of herbarium collections containing anywhere from hundreds to hundreds of thousands of dried plant samples, plant roots were a nuisance to preservation for several reasons. A full root system could complicate the collection process and exceed the dimensions of a standard herbarium sheet ( 16.5 inches by 11.75 inches ). Moreover, pests could be hiding in the soil attached to specimen roots, with the potential to destroy an entire collection if not treated promptly and aggressively The upshot of these complications was that roots were often not included in the samples at all. One 2019 study found that just a quarter of the specimens from four focal species studied at the herbarium included roots.

Botanist Mason Heberling, a co-author of that study, focused on 48 of the specimens that did contain roots, which were collected over a period of 127 years. Instead of fixating on the downsides of root systems, he set out to realize their potential as pristine, untapped time capsules.

“What got me excited and interested was that the specimens were kind of dirty,” he says. “I was awestruck that I was looking at a specimen that was collected over 100 years ago, and then by extension, I was also like, ‘Geez, there are pieces of dirt on the roots that are more than 100 years old.’”

Heberling, the associate curator of botany at the Carnegie Museum of Natural History in Pittsburgh, looked into the existing body of literature on plant roots in herbarium collections. He came up empty-handed, writing in 2022 that no study to his knowledge had conducted studies of root traits (like length, diameter, mass or microbial composition) in herbariums’ samples. Herbariums “are untapped repositories” of these kinds of data, he writes.

Heberling decided to undertake some of the research he thought had been overlooked. After scrutinizing dried samples in his collection, he noticed that the plants’ roots preserved troves of fungal DNA long after they had died. Much as humans outsource crucial parts of digestion to the microbes inhabiting our guts, plants rely on a similar microbial network to produce hormones, process nutrients and fight off disease. These fungi can envelop the roots or even penetrate their outer layers, as is true with a type called arbuscular mycorrhizal fungi. And as with the human microbiome, the question of what constitutes “self” versus “other” is largely a philosophical one: Remove the microbes from either a plant or a person, and the organism fails to thrive.

Heberling reasoned that a dried plant’s roots would have a unique assortment of fungi, acting as a snapshot of a given place and time. With that kind of data, he’d be able to answer fundamental questions about plant species that have been well represented in museum collections over the past two centuries. Are the arbuscular mycorrhizal fungi that colonize a species consistent throughout its geographic range, or could different regions be associated with their own microbes? And has the makeup of these communities changed over time, in response to climate change, acid rain and invasive species?

“Even though there’s a lot of really fascinating studies and a lot of fundamental knowledge about [root biology], there’s a lot that we don't know,” he says.

His first effort, detailed in that 2019 study , confirmed his hunch that fungal DNA could be successfully isolated from the roots of 21 of the 48 preserved specimens, which represented four species of western Pennsylvania wildflowers collected between 1881 and 2008. Moreover, Heberling and Case Western Reserve University biologist David Burke added an ingenious control experiment to make sure that these fungi were not contaminants introduced after the specimen was collected. They tried and failed to isolate arbuscular mycorrhizal fungi DNA from the specimens’ leaves. Since those fungi only colonize plant roots, the presence of fungi on the leaves would have indicated contamination.

Now, Heberling’s postdoctoral researcher Ben Lee is using herbariums’ records to reconstruct the fungal communities of white trillium, a wildflower found across eastern North America. By charting these communities across space and time, this research will let scientists peer into the past in an unprecedented way, seeing how our actions could be shaping the trajectory of a striking flower.

“The big global change question is: Have these mycorrhizal communities changed over time? Because we really don’t know. It’s invisible,” Heberling says. Lee, he adds, is “looking at the visible effects of these invisible players.”

Grounding models in the capabilities of roots

Plants play a key role in climate models due to their role as carbon sinks. They sequester carbon as well as other elements while they are alive by removing carbon dioxide from the air and converting it into sugars. Some of these sugars go into creating the roots; roots also burn sugar and release carbon back into the atmosphere. And variation in root forms and efficiencies change the amount of carbon and other nutrients taken up and recirculated by a given plant. But climate models historically have not incorporated the diversity of root systems into their calculations.

“A lot of the models that are trying to predict the climate of the Earth and carbon cycling are all focused on above-ground plant traits,” says Stephanie Kivlin, an ecologist and evolutionary biologist at the University of Tennessee, Knoxville. “Most of them don’t even include roots at all—they just assume roots are all the same.”

Kivlin realizes the need for truer root representation in these models, but she acknowledges that tweaking a large climate model isn’t as easy as inserting a line of code. Computers model the climate by solving a handful of complex equations about the movement and cycling of air, water and energy. Introducing variables, like information about root systems, can make the computer’s solution to these equations more accurate, but they also become much more difficult to solve. And the harder these equations become, the more time, computing power and resources they require.

Working within these constraints, Kivlin and her collaborators adjusted a global climate model to include arbuscular mycorrhizal fungi and ectomycorrhizal fungi, which do not penetrate the roots. These two types of fungi induce plants to cycle water, nitrogen and other elements in very different ways. She and her co-authors found that a climate model accounting for arbuscular mycorrhizal fungi and ectomycorrhizal fungi was 80 percent more accurate in predicting nitrogen cycling. When there is less nitrogen in the soil, plants cannot accumulate carbon as efficiently, limiting their potential as sinks. By accounting for the dichotomy between the two root fungi, Kivlin found an efficient way to improve a climate model while only introducing a single variable.

Bolstering crops with a greater understanding of their roots

One of the most important roles that microbes play for plants is upping the roots’ intake of vital nutrients like water, phosphorus, copper and zinc. The balance of these compounds determines a plant’s growth as well as its resilience in the face of extreme weather events. By understanding what an ideal root system looks like for a given plant species, farmers can breed two naturally robust plants together and create hardier varieties of crops.

Harnessing this vast potential to improve crops is why Jonathan Lynch , a recently retired Penn State biologist, devoted his career to studying roots.

“I didn’t go into science thinking I’d be a root biologist. I went into science thinking I was going to do something about world hunger,” he says. “But my work showed me clearly that the real thing going on here is with the roots.”

Global hunger soared to an all-time high in 2023, due to a combination of conflict and the effects of climate change. In January, the authors of a United Nations report estimated that nearly a quarter of the global population is drought-stricken. Lynch realized early on in his career that the differences between higher- and lower-yield crops were only exacerbated in poor conditions.

And in “bad soil,” as he terms it, “the difference between a good plant and a bad plant is the roots.” When the resources in soil are limited, resilient root systems can penetrate deeper and make the most of their environment.

But 40 years ago, the characteristics of a promising root system were ill-defined. So Lynch and his colleagues invented a protocol for assessing the roots of a plant that they termed “shovelomics.” The subdiscipline basically denotes the study of everything that can be uprooted with a shovel.

Shovelomics swaps out cutting-edge lab technology for that popular metal tool available at any hardware store. Lynch’s protocol for the subdiscipline involves identifying and digging up samples and then creating metrics by which multiple plants’ root systems can be judged. The number of the roots and the rate at which they branch; their length; their diameter; and the angles at which they emerge from the shoots of the plant can all make for rich comparisons.

When Lynch first submitted his paper on shovelomics in 2010, he says a journal editor threatened to bury it because of how silly the name sounded. Despite the early misgivings, “a lot of people have picked up shovelomics,” he says. A search for shovelomics on the research engine Google Scholar turned up over 1,200 academic papers.

But requiring that researchers resort to shoveling up entire plants to monitor their roots is still a barrier to discoveries, says Ahkami. “Unless it is at the end of the season or your experiment and you don’t need those plants anymore, you may not want to dig the whole plants up,” he says.

What if there were noninvasive ways of quantifying root systems? Some researchers are testing methods and technologies to study the roots while they remain in the ground. One Washington-based company, CID Bio-Science, creates minirhizotrons, which are transparent tubes and cameras installed in the ground to capture root growth in real time. For his part, Lynch recently co-wrote a new study that uses measurements of the element strontium in plant leaves to estimate the root lengths. An above-ground monitoring device may soon follow from this work, he says.

“You could even imagine a [device with a] light, so whenever you’re zapping the leaf of a deeper plant it displays a little green light, and a shallower one has a red light,” Lynch says.

Devices like these could help farmers and plant breeders select for hardier crop varieties—with thicker, longer or more dense roots that can absorb scarce nutrients—a marked shift from previous agricultural revolutions, according to Lynch. In the past, farmers applied innovations like chemical fertilizers and automated irrigation to maximize available nutrients for crops. As humans run up against limited resources, though, this strategy is no longer tenable.

“We can’t just fertilize and irrigate our way out of everything,” he says. “This is the second Green Revolution, and I think these roots are going to be key.”

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