已显示不同的结构在具有物理休眠(PY)的种子中充当水隙,在豆科中,它们通常位于肺门地区。然而,胸膜图的功能,叶外区域的一种结构,在豆科植物种子中很常见,仍然未知。我们的目的是回顾有关豆科胸膜图发生的文献,确定胸膜图是否可以打开,并比较了11种番泻叶种子水隙的功能形态解剖。
吸胀试验表明,所有11个物种都有PY。使用光学和扫描电子显微镜研究了种子的肺门和肺门外区域的结构特征,并进行染料追踪以追踪水通过种皮的途径。
据报道,有37个豆科植物属的胸膜图。塞纳物种之间的水隙不同,带镜头,宫门,PY破裂后,微孔和胸膜图吸收水。在SennaAlata种子中,只有胸膜图作为水隙,而在肾形链球菌和silvestris中,水通过胸膜图和肺门区域进入种子。在Alata和S.reniformis的胸膜图中,栅栏层向外移动,暴露沙漏细胞,而在S.silvestris,栅栏层被破坏了。
胸膜图在所检查的11种塞纳物种中充当水隙,但它在其他人中不起作用。由于在栅栏层中形成线性狭缝,因此会打开胸膜图。胸膜图通过创造一个广阔的开口而具有功能意义,水可以到达胚胎并开始发芽。这是关于胸膜图作为水隙的第一份报告。因为这种结构至少由37属共有,这也可能是许多其他豆类物种的水缺口。
Different structures have been shown to act as a water gap in seeds with physical dormancy (PY), and in Fabaceae they are commonly located in the hilar region. However, the function of the pleurogram, a structure in the extra-hilar region that is common in legume seeds, remains unknown. Our aims were to review the literature for occurrence of the pleurogram in Fabaceae, determine if the pleurogram can open, and compare the functional morpho-anatomy of water gaps in seeds of 11 Senna species.
Imbibition tests showed that all 11 species had PY. Structural features of the hilar and extra-hilar regions of the seeds were investigated using light and scanning electron microscopy, and dye-tracking was performed to trace the pathways of water through the seed coat.
A pleurogram has been reported for 37 legume genera. Water gaps differed among Senna species, with lens,
hilum, micropyle and pleurogram taking up water after PY was broken. In Senna alata seeds, only the pleurogram acted as a water gap, whereas in S. reniformis and S. silvestris water entered the seed through both the pleurogram and the hilar region. In the pleurogram of S. alata and S. reniformis, the palisade layer moved outward, exposing the hourglass cells, whereas in S. silvestris the palisade layer was broken.
The pleurogram acts as a water gap in some of the 11 Senna species examined, but it is non-functional in others. Opening the pleurogram occurs due to the formation of a linear slit in the palisade layer. The pleurogram is of functional significance by creating a wide opening, whereby water can reach the embryo and start germination. This is the first report of the pleurogram functioning as a water gap. Because this structure is shared by at least 37 genera, it also may be a water gap in many other legume species.