Sato Kei, Jitsuyama Yutaka, Yamada Tetsuya, Liu Baohui, Abe Jun
Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
School of Life Sciences, Guangzhou University, Guangzhou 510006, China.
Breed Sci. 2019 Jun;69(2):364-370. doi: 10.1270/jsbbs.18181. Epub 2019 May 18.
Soybean () seeds are prone to imbibition injury caused by a rapid uptake of water. Genetic variation in imbibition injury tolerance is well documented, but the underlying mechanisms remain unclear. The aim of this study was to clarify the role of the aleurone layer of seed coat in the tolerance and its structural differences between tolerant and susceptible cultivars. Imbibition injury tolerance was closely related to the water absorption rate of seeds, which was regulated by the aleurone layer of the seed coat. Cryo-scanning electron microscopy analysis revealed that water absorbed in seed coats entered the seed preferentially through the aleurone layer of the top area above the raphe. In susceptible cultivars, the cell walls of the aleurone layer facing the cotyledon in this area were thin and the surface showed shallow depression-like structures, a distinct structure different from those of the tolerant cultivars, which had aleurone cells with thick outer cell walls and smooth and stripe-like deposits. The differences in the structural features of the cell walls and surfaces of aleurone cells in the top area of the seed may be responsible for the difference in the extent of imbibition injury between susceptible and tolerant cultivars.
大豆（）种子容易因快速吸水而受到吸胀损伤。吸胀损伤耐受性的遗传变异已有充分记录，但其潜在机制仍不清楚。本研究的目的是阐明种皮糊粉层在耐受性中的作用及其在耐受性和敏感性品种之间的结构差异。吸胀损伤耐受性与种子的吸水率密切相关，而种子吸水率受种皮糊粉层调节。冷冻扫描电子显微镜分析表明，种皮吸收的水分优先通过珠脊上方顶部区域的糊粉层进入种子。在敏感品种中，该区域面向子叶的糊粉层细胞壁较薄，表面呈现浅凹陷状结构，这与耐受性品种明显不同，耐受性品种的糊粉层细胞具有较厚的外部细胞壁以及光滑的条纹状沉积物。种子顶部区域糊粉层细胞的细胞壁和表面结构特征的差异可能是敏感品种和耐受性品种吸胀损伤程度不同的原因。
