Circadian rhythms are associated with shoot architecture in natural settings

First author: Matthew J. Rubin; Affiliations: University of Wyoming (怀俄明大学): Laramie, USA

Corresponding author: Matthew J. Rubin

Circadian rhythms (昼夜节律) are key regulators of diverse biological processes under controlled settings. Yet, the phenotypic and fitness consequences of quantitative variation in circadian rhythms remain largely unexplored in the field. As with other pathways, phenotypic characterization of circadian outputs in the field may reveal novel clock functions. Across consecutive (连续的) growing seasons, we test for associations between clock variation and flowering phenology, plant size, shoot architecture, and fruit set (座果) in clock mutants and segregating progenies of Arabidopsis thaliana expressing quantitative variation in circadian rhythms. Using structural equation modeling (结构方程模型), we find that genotypic variation in circadian rhythms within a growing season is associated directly with branching, which in turn affects fruit production. Consistent with direct associations between the clock and branching in segregating progenies, cauline branch (茎的分枝) number is lower and rosette branch (莲座分枝) number higher in a short‐period mutant relative to wild‐ ype and long‐period genotypes, independent of flowering time. Differences in branching arise from variation in meristem fate as well as leaf production rate before flowering and attendant increases in meristem number. Our results suggest that clock variation directly affects shoot architecture in the field, suggesting a novel clock function and means by which the clock affects performance.

昼夜节律是控制环境条件下多个生物学进程的重要调控子。然而，目前对于野外昼夜节律的数量变异所导致的表型和适应性结果还有待研究。另外，野外条件下昼夜节律产物的表型鉴定可能会揭示昼夜节律新功能。在连续的生在季节，作者测试了昼夜节律突变体中，昼夜节律变异与开花物候学、植物大小、茎尖结构和座果之间的关联，以及表达昼夜节律数量变异的拟南芥的分离子代。作者借用结构方程模型发现在生长季节中昼夜节律的表型变异直接与分枝相关，进而会影响到果实产量。与分离子代中昼夜节律和分枝直接相关的结果一致，相比于野生型和长周期基因型，在短周期突变体中茎生分枝数量较低，而莲座分枝数量更高，并且这些表现独立于开花时间。开花前的分生速率和叶产量速率分枝，以及伴随着的分生组织数量增加的变异导致了分枝的差异。本文的结果表明昼夜节律直接影响了野外茎尖结构，揭示了昼夜节律的一个新的功能，其能够影响植物的表型表现。

shoot维基百科的定义是：In botany, shootsconsist of stems including their appendages, the leaves and lateral buds, flowering stems and flower buds. 一年生植物的shoot就是种子萌发向上生长的部分；多年生植物分为草本和木本，草本shoot是指地上部分春天新生长的枝叶；木本shoot是指春天新长出的茎或花。

doi: https://doi.org/10.1111/nph.15162

Journal: New Phytologist

First Published date: 19 April, 2018

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