Improvement of creep meter to estimate physical properties of cell wall for selection of crop cultivars

我们试图改进蠕变材料来估计物理性质，这是植物形态发生的主要因素。以水稻矮秆突变体为材料，研究了赤霉素(GA)诱导叶鞘生长的机制。Tan-Ginbozu)预先用GA生物合成抑制剂处理。赤霉酸(GA)促进了第二叶鞘的生长，而生长素则没有。有丝分裂指数和细胞大小的测量表明，GA促进了细胞的伸长，而不是细胞的分裂。赤霉素提高了叶鞘伸长区细胞壁的延伸性。它还增加了叶鞘中包括糖在内的渗透溶质的总量，但没有增加细胞汁液的渗透浓度，这是因为细胞吸收水分而增加了细胞体积。在GA诱导生长的后期，叶鞘细胞中的淀粉颗粒完全消失，而对照植株中仍有致密的淀粉颗粒。这些发现表明，GA通过增加细胞壁的延伸性来提高细胞的伸长率，而渗透浓度通过淀粉的降解保持不变。

We attempted to improve creep mater to estimate physical properties, which are major factors for plant morphogenesis. We also attempted to establish physical model to adapt cell wall loosening.The mechanism of gibberellin (GA) -induced leaf sheath growth was examined using a dwarf mutant of rice (Oryza sativa L. cv. Tan-ginbozu) treated in advance with an inhibitor of GA biosynthesis. Gibberellic acid (GA) enhanced the growth of the second leaf sheath, but auxins did not. Measurement of the mitotic index and cell size revealed that cell elongation rather than cell division is promoted by GA. GA increased the extensibility of cell walls in the elongation zone of the leaf sheath. It also increased the total amount of osmotic solutes including sugars in the leaf sheath, but did not increase the osmotic concentration of the cell sap, due to accompanying increase in cell volume by water absorption. In the later stage of GA-induced growth, starch granules completely disappeared from leaf sheath cells, whereas dense granules remained in control plants. These findings indicate that GA enhances cell elongation by increasing wall extensibility, osmotic concentration being kept unchanged by starch degradation.