结球白菜反义BcpLH基因转化株幼苗对生长激素的反应

Reactions of Antisense BcpLH Gene Transgenic Seedlingsof Chinese Cabbage to Auxin

4种浓度的植物生长素处理苗期的结球白菜反义BcpLH基因转化株后发现, IAA处理的转化株叶色变淡,叶片外卷。激素浓度在0 ~ 0 01mmol·L-1和1 0~10 0mmol·L-1两个区域时,转化株和非转化株的叶形指数略有增加,而在0 01~1 0mmol·L-1范围内,两者的叶形指数均呈下降趋势,表明IAA在此浓度范围内,叶肉细胞沿主叶脉方向的纵向生长受到的抑制强于横向生长所受到的抑制。虽然0 1mmol·L-1以上浓度的IAA对转化株和非转化株的叶柄生长都具有抑制作用,但与非转化株相比,转化株的反应较为迟钝。对非转化株的下胚轴生长有不同作用的IAA拐点浓度是0 01mmol·L-1,而转化株的拐点浓度是1 0mmol·L-1。IAA对转化株和非转化株的主根生长都有促进作用,但转化株对IAA的敏感性弱于非转化株。

The leaves of transgenic seedlings treated with four concentrations of IAA exhibit yellow-green and revolute.The leaf shape indexes (LSIs) of transgenic and control seedlings increase lightly when the IAA treatment concentrations are in two regions of 0～0.01 mmol·L^(-1) and 1.0～10.0 mmol·L^(-1) respectively,while LSIs decrease when IAA concentrations are between 0.01 mmol·L^(-1) and 1.0 mmol·L^(-1), this implies the depression effect on the growth in longitudinal is greater than that in transversal for both transgenic and control mesophyllous cells.The growth of leaf stalks of transgenic seedlings is less sensitive than that of the control ones when IAA concentration exceeds 0.1 mmol·L^(-1).The IAA turning point concentration is 0.01 mmol·L^(-1) for the growth effect of control seedling hypocotyls, while it is 1.0 mmol·L^(-1) for transgenic hypocotyls. IAA has an acceleration effect on the main root growth of both transgenic and control seedlings, but the former is less sensitive to IAA.