Ring-shaped chalkiness increased by dry wind in rice : Direct measurement of turgor in endosperm cells and the role of osmotic adjustment at low water potential

在水稻灌浆期，焚风引起的干燥风典型地增加了水稻（Oryza sativa L.）植物本研究旨在利用改良的细胞压力探针，从生理学角度探讨胚乳细胞中环状垩白的发生机制。内胚乳细胞，其中环形垩白的频率最高的观察，保持膨压渗透调节空间，即使在低水势之前的垩白形成。结果还表明，最终粒重和^<13>C在穗和籽粒中的分配均未下降。因此，可以得出结论，膨压的维持渗透调节有助于水分亏缺下的粮食发展焚风，和渗透调节有暂时抑制胚乳中淀粉积累的作用，导致在焚风引起的水分亏缺条件下的环形垩白籽粒。

Foehn-induced dry wind during grain filling typically increased ring-shaped chalky kernels in rice(Oryza sativa L.) plants. The objective of this study was to physiologically investigate mechanisms of the occurrence of ring-shaped chalkiness in the growing endosperm cells by utilizing the improved cell pressure probe. The inner endosperm cells, where the highest frequency of ring-shaped chalkiness was observed, maintained turgor by osmotic adjustment spatially even at low water potentials prior to the chalky formation. The results also indicated that neither the final grain weight nor^<13> C distribution in both panicles and the kernels was declined. Therefore, it was concluded that turgor maintenance by osmotic adjustment contributes to grain development under water deficit by foehn, and osmotic adjustment has a role in temporally inhibiting starch accumulation in endosperms, resulting in ring-shaped chalky kernels under foehn-induced water deficit conditions.