Chatterjee Jolly, Dionora Jacqueline, Elmido-Mabilangan Abigail, Wanchana Samart, Thakur Vivek, Bandyopadhyay Anindya, Brar Darshan S, Quick William Paul
C4 Rice Center, Genetics and Biotechnology Division, International Rice Research Institute, Los Baños, DAPO BOX 7777, Metro Manila, Philippines.
Plant Breeding, Genetics and Biotechnology Division, International Rice Research Institute, Los Baños, DAPO BOX 7777, Metro Manila, Philippines.
PLoS One. 2016 Oct 28;11(10):e0164532. doi: 10.1371/journal.pone.0164532. eCollection 2016.
Rice contains genetically and ecologically diverse wild and cultivated species that show a wide variation in plant and leaf architecture. A systematic characterization of leaf anatomy is essential in understanding the dynamics behind such diversity. Therefore, leaf anatomies of 24 Oryza species spanning 11 genetically diverse rice genomes were studied in both lateral and longitudinal directions and possible evolutionary trends were examined. A significant inter-species variation in mesophyll cells, bundle sheath cells, and vein structure was observed, suggesting precise genetic control over these major rice leaf anatomical traits. Cellular dimensions, measured along three growth axes, were further combined proportionately to construct three-dimensional (3D) leaf anatomy models to compare the relative size and orientation of the major cell types present in a fully expanded leaf. A reconstruction of the ancestral leaf state revealed that the following are the major characteristics of recently evolved rice species: fewer veins, larger and laterally elongated mesophyll cells, with an increase in total mesophyll area and in bundle sheath cell number. A huge diversity in leaf anatomy within wild and domesticated rice species has been portrayed in this study, on an evolutionary context, predicting a two-pronged evolutionary pathway leading to the 'sativa leaf type' that we see today in domesticated species.
水稻包含遗传和生态多样的野生及栽培品种,这些品种在植株和叶片结构上表现出广泛的差异。对叶片解剖结构进行系统表征对于理解这种多样性背后的动态机制至关重要。因此,研究了跨越11个遗传多样的水稻基因组的24个稻种的叶片解剖结构,包括横向和纵向,并探讨了可能的进化趋势。观察到叶肉细胞、维管束鞘细胞和叶脉结构存在显著的种间差异,这表明这些主要的水稻叶片解剖特征受到精确的遗传控制。沿着三个生长轴测量的细胞尺寸进一步按比例组合,构建三维(3D)叶片解剖模型,以比较完全展开叶片中主要细胞类型的相对大小和方向。对祖先叶片状态的重建显示,最近进化的水稻品种具有以下主要特征:叶脉较少、叶肉细胞更大且横向拉长,叶肉总面积和维管束鞘细胞数量增加。本研究在进化背景下描绘了野生和驯化水稻品种叶片解剖结构的巨大多样性,预测了导致我们今天在驯化品种中看到的“栽培稻叶型”的双叉进化途径。