长穗颈(eui)水稻上部节间伸长与植物激素的关系

选取含有诱变的长穗颈基因eui1、eui2和野生型基因Eui的水稻(OryzasativaL.)协青早保持系3个等基因系,通过供试植株在不同生育期的GA1和ABA含量测定及喷施GA合成抑制剂,并辅之器官删除试验等方法,探索长穗颈水稻上部节间伸长的生理机制.结果表明,在抽穗期,含eui1的协青早保持系XeB1幼穗和剑叶里的GA1含量显著增加,分别约为对照协青早B的16倍和3.4倍,其GA1/ABA比值也明显增加;含eui2的XeB2幼穗和剑叶里的GA1含量显著提高,但仅在剑叶里GA1/ABA比值明显增加,其幼穗内的GA1水平显著低于XeB1.GA合成抑制剂S3307处理使XeB1和XeB2的株高生长均受到严重抑制.删除幼穗使XeB1最上节间伸长的受抑程度远大于XeB2和XB.由此推测,在抽穗期,eui1能使水稻自身产生GA1,高含量的GA1诱导了长穗颈水稻最上节间的剧烈伸长;在促进最上节间的伸长方面eui1强于eui2.图5表1参12

RELATION BETWEEN UPPER INTERNODE ELONGATION OF RICE WITH eui GENE AND PLANT HORMONES

Three Xieqingzao rice allelic lines (Oryza sativa L.) possessing mutagenic elongated upper internode genes eui1, eui2 and Eui were used to study the mechanism of internodal elongation of eui1 and eui2 rice by determining endogenous gibberellin A_ 1 (GA_ 1) and abscisic acid (ABA) levels in various organs at different growth stages, applying GA biosynthesis inhibitor to eui plants and removing some organs of eui rice. The results indicated that at heading stage Xieqingzao maintainer line XeB1 with eui1 obviously increased its GA_ 1 contents both in panicles and flag leaves, about 16 times and 3.4 times more than those of the control XB, respectively, and the GA_ 1/ABA rates of eui1 rice also raised greatly; XeB2 with eui2 also greatly increased its GA_ 1 contents in panicles and flag leaves, but only GA_ 1/ABA rates increased in flag leaves and GA_ 1 content in the panicle was obviously lower than that of XeB1. When XeB1 and XeB2 were treated with GA biosynthesis inhibitor S_ 3307 at late booting stage, the growth of XeB1 and XeB2 was heavily inhibited. When the panicles of XeB1, XeB2 and XB were removed at late booting stage, the elongation of uppermost internode of XeB1 was inhibited much more than that of XeB2 and XB. It would be inferred that both eui1 and eui2 could promote eui rice to produce GA_ 1 significantly and high GA_ 1 content induce eui rice to elongate its uppermost internode very rapidly at heading stage. eui1 promoted the elongation of rice uppermost internode more vigorously than eui2. Fig 5, Tab 1, Ref 12