skip to main content


Title: Multilab EcoFAB study shows highly reproducible physiology and depletion of soil metabolites by a model grass
Summary

There is a dynamic reciprocity between plants and their environment: soil physiochemical properties influence plant morphology and metabolism, and root morphology and exudates shape the environment surrounding roots. Here, we investigate the reproducibility of plant trait changes in response to three growth environments.

We utilized fabricated ecosystem (EcoFAB) devices to grow the model grassBrachypodium distachyonin three distinct media across four laboratories: phosphate‐sufficient and ‐deficient mineral media allowed assessment of the effects of phosphate starvation, and a complex, sterile soil extract represented a more natural environment with yet uncharacterized effects on plant growth and metabolism.

Tissue weight and phosphate content, total root length, and root tissue and exudate metabolic profiles were consistent across laboratories and distinct between experimental treatments. Plants grown in soil extract were morphologically and metabolically distinct, with root hairs four times longer than with other growth conditions. Further, plants depleted half of the metabolites investigated from the soil extract.

To interact with their environment, plants not only adapt morphology and release complex metabolite mixtures, but also selectively deplete a range of soil‐derived metabolites. The EcoFABs utilized here generated high interlaboratory reproducibility, demonstrating their value in standardized investigations of plant traits.

 
more » « less
NSF-PAR ID:
10452907
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
New Phytologist
Volume:
222
Issue:
2
ISSN:
0028-646X
Page Range / eLocation ID:
p. 1149-1160
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Summary

    Arbuscular mycorrhizal (AM) fungi are the most abundant plant symbiont and a major pathway of carbon sequestration in soils. However, their basic biology, including their activity throughout a 24‐h day : night cycle, remains unknown.

    We employed thein situSoil Ecosystem Observatory to quantify the rates of diurnal growth, dieback and net productivity of extra‐radicalAMfungi.AMfungal hyphae showed significantly different rates of growth and dieback over a period of 24 h and paralleled the circadian‐driven photosynthetic oscillations observed in plants.

    The greatest rates (and incidences) of growth and dieback occurred between noon and 18:00 h. Growth and dieback events often occurred simultaneously and were tightly coupled with soil temperature and moisture, suggesting a rapid acclimation of the external phase ofAMfungi to the immediate environment.

    Changes in the environmental conditions and variability of the mycorrhizosphere may alter the diurnal patterns of productivity ofAMfungi, thereby modifying soil carbon sequestration, nutrient cycling and host plant success.

     
    more » « less
  2. Summary

    Root system architecture (RSA) is a critical aspect of plant growth and competitive ability. Here we used two independently evolved strains of weedy rice, a de‐domesticated form of rice, to study the evolution of weed‐associatedRSAtraits and the extent to which they evolve through shared or different genetic mechanisms.

    We characterised 98 two‐dimensional and three‐dimensionalRSAtraits in 671 plants representing parents and descendants of two recombinant inbred line populations derived from two weed × crop crosses. A random forest machine learning model was used to assess the degree to which root traits can predict genotype and the most diagnostic traits for doing so. We used quantitative trait locus (QTL)mapping to compare genetic architecture between the weed strains.

    The two weeds were distinguishable from the crop in similar and predictable ways, suggesting independent evolution of a ‘weedy’RSAphenotype. Notably, comparativeQTLmapping revealed little evidence for shared underlying genetic mechanisms.

    Our findings suggest that despite the double bottlenecks of domestication and de‐domestication, weedy rice nonetheless shows genetic flexibility in the repeated evolution of weedyRSAtraits. Whereas the root growth of cultivated rice may facilitate interactions among neighbouring plants, the weedy rice phenotype may minimise below‐ground contact as a competitive strategy.

     
    more » « less
  3. Summary

    Diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DAG) to generate phosphatidic acid (PA), and bothDAGandPAare lipid mediators in the cell. Here we show thatDGK1 in rice (Oryza sativa) plays important roles in root growth and development.

    Two independentOsDGK1‐knockout (dgk1) lines exhibited a higher density of lateral roots (LRs) and thinner seminal roots (SRs), whereasOsDGK1‐overexpressing plants displayed a lowerLRdensity and thickerSRsthan wild‐type (WT) plants.

    Overexpression ofOsDGK1led to a decline in theDGKsubstrateDAGwhereas specificPAspecies decreased indgk1roots. Supplementation ofDAGtoOsDGK1‐overexpressing seedlings restored theLRdensity andSRthickness whereas application ofPAtodgk1seedlings restored theLRdensity andSRthickness to those of theWT. In addition, treatment of rice seedlings with theDGKinhibitor R59022 increased the level ofDAGand decreasedPA, which also restored the root phenotype ofOsDGK1‐overexpressing seedlings close to that of theWT.

    Together, these results indicate thatDGK1 and associated lipid mediators modulate rice root architecture;DAGpromotesLRformation and suppressesSRgrowth whereasPAsuppressesLRnumber and promotesSRthickness.

     
    more » « less
  4. Abstract

    The domestic sunflower (Helianthus annuusL. cv. ‘Giganteus’) has been used since the 19th century as a model plant for the study of seedling development in darkness and white light (WL) (scoto‐versusphotomorphogenesis). However, most pertinent studies have focused on the developmental patterns of the hypocotyl and cotyledons, whereas the root system has been largely ignored.

    In this study, we analysed entire sunflower seedlings (root and shoot) and quantified organ development in the above‐ and belowground parts of the organism under natural (non‐sterile) conditions.

    We document that seedlings, raised in moist vermiculite, are covered with methylobacteria, microbes that are known to promote root development inArabidopsis. Quantitative data revealed that during photomorphogenesis inWL, the root system expands by 90%, whereas stem elongation is inhibited, and hook opening/cotyledon expansion occurs. Root morphogenesis may be mediatedviaimported sucrose provided by the green, photosynthetically active cotyledons. This hypothesis is supported by the documented effect of sucrose on the induction of lateral root initials in sunflower cuttings. Under these experimental conditions, phytohormones (auxin, cytokinin, brassinolide) exerted little effect on root and cotyledon expansion, and no hormone‐induced initiation of lateral roots was observed.

    It is concluded that sucrose not only acts as an energy source to fuel cell metabolism but is also a shoot‐derived signalling molecule that triggers root morphogenesis.

     
    more » « less
  5. Summary

    Faithful chromosome segregation is required for both mitotic and meiotic cell divisions and is regulated by multiple mechanisms including the anaphase‐promoting complex/cyclosome (APC/C), which is the largest known E3 ubiquitin‐ligase complex and has been implicated in regulating chromosome segregation in both mitosis and meiosis in animals. However, the role of theAPC/C during plant meiosis remains largely unknown. Here, we show that ArabidopsisAPC8is required for male meiosis.

    We used a combination of genetic analyses, cytology and immunolocalisation to define the function of AtAPC8 in male meiosis.

    Meiocytes fromapc8‐1plants exhibit several meiotic defects including improper alignment of bivalents at metaphase I, unequal chromosome segregation during anaphaseII, and subsequent formation of polyads. Immunolocalisation using an antitubulin antibody showed thatAPC8 is required for normal spindle morphology. We also observed mitotic defects inapc8‐1,including abnormal sister chromatid segregation and microtubule morphology.

    Our results demonstrate that ArabidopsisAPC/C is required for meiotic chromosome segregation and thatAPC/C‐mediated regulation of meiotic chromosome segregation is a conserved mechanism among eukaryotes.

     
    more » « less