Laboratory for Integrated Molecular Plant Physiology Research (IMPRES), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerpen, Belgium.
Laboratorio de Fisiología de Estrés Abiótico en Plantas, Unidad de Biotecnología 1, IIB-INTECH - CONICET - UNSAM, Chascomús, Argentina.
New Phytol. 2017 Jul;215(1):299-308. doi: 10.1111/nph.14573. Epub 2017 Apr 25.
Little is known about how the characteristic differences in organ size between species are regulated. At the cellular level, the size of an organ is strictly regulated by cell division and expansion during its development. We performed a meta-analysis of the growth parameters of roots, and Graminae and eudicotyledonous leaves, to address the question of how quantitative variation in these two processes contributes to size differences across a range of species. We extracted or derived cellular parameters from published kinematic growth analyses. These data were subjected to linear regression analyses to identify the parameters that determine differences in organ growth. Our results demonstrate that, across all species and organs, similar conclusions can be made: cell number rather than cell size determines the final size of plant organs; cell number is determined by meristem size rather than the rate at which cells divide; cells that are small when leaving the meristem compensate by expanding for longer; mature cell size is primarily determined by the duration of cell expansion. These results identify the regulation of the transition from cell division to expansion as the key cellular mechanism targeted by the evolution of organ size.
关于物种间器官大小特征差异是如何调节的，人们知之甚少。在细胞水平上，器官的大小严格由其在发育过程中的细胞分裂和扩张来调节。我们对根、禾本科植物和真双子叶植物叶片的生长参数进行了荟萃分析，以解决这两个过程的定量变异如何导致一系列物种间大小差异的问题。我们从已发表的运动学生长分析中提取或推导了细胞参数。对这些数据进行线性回归分析，以确定决定器官生长差异的参数。我们的结果表明，在所有物种和器官中，都可以得出类似的结论：细胞数量而非细胞大小决定植物器官的最终大小；细胞数量由分生组织大小决定，而不是由细胞分裂速度决定；离开分生组织时较小的细胞通过延长扩张来补偿；成熟细胞大小主要由细胞扩张的持续时间决定。这些结果确定了从细胞分裂到扩张的过渡的调节是器官大小进化的目标关键细胞机制。
