scholarly journals MicroRNA156‐mediated changes in leaf composition lead to altered photosynthetic traits during vegetative phase change

2020 ◽  
Author(s):  
Erica H. Lawrence ◽  
Clint J. Springer ◽  
Brent R. Helliker ◽  
R. Scott Poethig
Keyword(s):  
Phase Change ◽  
Vegetative Phase ◽  
Vegetative Phase Change ◽  
Leaf Composition ◽  
Photosynthetic Traits

scholarly journals miR156-mediated changes in leaf composition lead to altered photosynthetic traits during vegetative phase change

2020 ◽  
Author(s):  
Erica H. Lawrence ◽  
Clint J. Springer ◽  
Brent R. Helliker ◽  
R. Scott Poethig
Keyword(s):  
Phase Change ◽  
Plant Morphology ◽  
Leaf Traits ◽  
Plant Size ◽  
Photosynthetic Performance ◽  
List Type ◽  
Vegetative Phase ◽  
Vegetative Phase Change ◽  
Light Levels ◽  
Leaf Composition

SummaryPlant morphology and physiology change with growth and development. Some of these changes are due to change in plant size and some are the result of genetically programmed developmental transitions. In this study we investigate the role of the developmental transition, vegetative phase change (VPC), on morphological and photosynthetic changes.We used overexpression of miR156, the master regulator of VPC, to modulate the timing of VPC in Populus tremula x alba, Zea mays and Arabidopsis thaliana to determine its role in trait variation independent of changes in size and overall age.Here we find that juvenile and adult leaves in all three species photosynthesize at different rates and that these differences are due to phase-dependent changes in specific leaf area (SLA) and leaf N but not photosynthetic biochemistry. Further, we found juvenile leaves with high SLA were associated with better photosynthetic performance at low light levels.This study establishes a role for VPC in leaf composition and photosynthetic performance across diverse species and environments. Variation in leaf traits due to VPC are likely to provide distinct benefits under specific environments and, as a result, selection on the timing of this transition could be a mechanism for environmental adaptation.

scholarly journals Sugar promotes vegetative phase change in Arabidopsis thaliana by repressing the expression of MIR156A and MIR156C

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Li Yang ◽  
Mingli Xu ◽  
Yeonjong Koo ◽  
Jia He ◽  
R Scott Poethig
Keyword(s):  
Arabidopsis Thaliana ◽  
Phase Change ◽  
Nutrient Availability ◽  
Developmental Timing ◽  
Vegetative Phase ◽  
Adult Transition ◽  
Vegetative Phase Change ◽  
Exogenous Glucose ◽  
Exogenous Sugar ◽  
Signaling Activity

Nutrients shape the growth, maturation, and aging of plants and animals. In plants, the juvenile to adult transition (vegetative phase change) is initiated by a decrease in miR156. In Arabidopsis, we found that exogenous sugar decreased the abundance of miR156, whereas reduced photosynthesis increased the level of this miRNA. This effect was correlated with a change in the timing of vegetative phase change, and was primarily attributable to a change in the expression of two genes, MIR156A and MIR156C, which were found to play dominant roles in this transition. The glucose-induced repression of miR156 was dependent on the signaling activity of HEXOKINASE1. We also show that the defoliation-induced increase in miR156 levels can be suppressed by exogenous glucose. These results provide a molecular link between nutrient availability and developmental timing in plants, and suggest that sugar is a component of the leaf signal that mediates vegetative phase change.

scholarly journals VAL genes regulate vegetative phase change via miR156-dependent and independent mechanisms

2021 ◽  
Author(s):  
Jim P. Fouracre ◽  
Jia He ◽  
Victoria J. Chen ◽  
Simone Sidoli ◽  
R. Scott Poethig
Keyword(s):  
Transcription Factors ◽  
Phase Change ◽  
Temporal Dynamics ◽  
Epigenetic Silencing ◽  
Developmental Transitions ◽  
Vegetative Phase ◽  
Vegetative Phase Change ◽  
Adult Growth ◽  
Epigenetic Repression ◽  
Polycomb Repressive Complex 1

SummaryHow organisms control when to transition between different stages of development is a key question in biology. In plants, epigenetic silencing by Polycomb repressive complex 1 (PRC1) and PRC2 plays a crucial role in promoting developmental transitions, including from juvenile-to-adult phases of vegetative growth. It is well established that PRC1/2 repress the master regulator of vegetative phase change, miR156, leading to the transition to adult growth, but how this process in temporally regulated is unknown. Here we investigate whether transcription factors in the VIVIPAROUS/ABI3-LIKE (VAL) gene family provide the temporal signal for the epigenetic repression of miR156. Exploiting a novel val1 allele, we found that VAL1 and VAL2 redundantly regulate vegetative phase change by controlling the overall level, rather than temporal dynamics, of miR156 expression. Furthermore, we discovered that VAL1 and VAL2 also act independently of miR156 to control this important developmental transition.

scholarly journals Leaf architecture, lignification, and tensile strength during vegetative phase change in Zea mays

2011 ◽  
Vol 77 (3) ◽  
pp. 181-188 ◽  
Author(s):  
Ronald A. Balsamo ◽  
Joseph A.J. Orkwiszewski
Keyword(s):  
Tensile Strength ◽  
Zea Mays ◽  
Phase Change ◽  
Leaf Morphology ◽  
Failure Load ◽  
Width Ratio ◽  
Individual Plant ◽  
Vegetative Phase ◽  
Vegetative Phase Change ◽  
Adult Phase

Background and Aims: Leaf morphology, anatomy, degree of lignification, and tensile strength were studied during vegetative phase change in an inbred line of <em>Zea mays</em> (OH43 x W23) to determine factors that influence mechanical properties during development. Methods: Tensometer, light microscopy, histochemistry. Key results: Mature leaf length increased linearly with plant development, peaked at leaves 7 and 8 (corresponding to the onset of the adult phase) and then declined. Leaf width was stable for leaves 1 through 3, increased to leaf 7, remained stable to leaf 10, and then declined through leaf 13. Lamina thickness was highest for leaf 1 and decreased throughout development. Leaf failure load to width ratio and failure load to thickness ratio increased with development suggesting that changes in leaf morphology during development do not entirely account for increases in failure load. Histochemical analyses revealed that leaf tensile strength correlates with percent lignification and the onset of anatomical adult features at various developmental stages. Conclusions: These data demonstrate that in <em>Zea mays</em> lignification of the midrib parenchyma and epidermis may be directly correlated with increased tensile strength associated with phase change from juvenility to adulthood. Failure load and resultant tensile strength values are primarily determined by the percent tissue lignification and the appearance of leaf architectural characters that are associated with the transition from the juvenile to the adult phase. Increased mechanical stability that occurs during the phase transition from juvenility to adulthood may signify a fundamental change in strategy for an individual plant from rapid growth (survival) to reproduction.

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