G蛋白调节剂和花柱S-核糖核酸酶对花粉管生长及其钙离子浓度的影响  

Effects of G-Protein Regulators and Stylar S-RNase on the Growth and Ca^(2+) Concentration of Pyrus pyrifolia Pollen Tube

作　　者：赵彩平[1] 徐国华[2] 张绍铃[1] 刘珠琴[1] 王春雷[1] 

机构地区：[1]南京农业大学园艺学院 [2]江苏教育学院生物系,南京210013

出　　处：《植物生理与分子生物学学报》2007年第5期395-401,共7页Journal Of Plant Physiology and Molecular Biology

基　　金：高校博士学科点专项科研基金项目(No.B200523)资助。~~

摘　　要：以‘丰水’和‘幸水’梨花柱及花粉为试材,用激光共聚焦显微技术,研究了离体条件下G蛋白活性调节剂和花柱S-RNA酶对花粉管生长及其游离Ca^(2+)浓度的影响。结果表明:G蛋白激活剂CTX可促进花粉管生长,且可解除花柱S-RNA酶对自身花粉管生长的抑制作用;G蛋白抑制荆PTX和花柱S-RNA酶共同处理使异体的花粉管生长受到抑制。CTX处理使花粉管尖端区的[Ca^(2+)]_i明显升高,花柱S-RNA酶处理引起自身花粉管尖端区的[Ca^(2+)]_i梯度消失;CTX和花柱S-RNA酶共同处理则使自身花粉管内的[Ca^(2+)J_i表现出两者单独处理时的综合特征;而花柱S-RNA酶和PTX共同处理后,异体的花粉管内[Ca^(2+)]_i表现出先升高后下降的趋势。The effects of G protein regulators and stylar S-RNase on the growth and [Ca^2＋]i changes of the Pyrus pyrifolia pollen tube were investigated using Laser Confocal Scanning Microscope （LCSM）. The results indicated that： （1） The growth of ‘Housui＇ pollen tube could be inhibited by its stylar S-RNase and pertussis toxin （PTX）, the in- hibitor of heterotrimeric G protein. While ‘Kousui＇ stylar S-RNase had little effect on the growth of ’Housui＇ pollen tube; cholera toxin （CTX）, the activator of heterotrimeric G protein, could pro- mote pollen tube growth and eliminate the sup- pression of stylar S-RNase on the growth of self- pollen tube, but the growth of ‘Housui＇ pollen tube could be arrested under the co-action of PTX and S-RNase from ‘Kousui＇ （Fig. 1）. （2） Treatments with different stylar S-RNase and G protein regu- lators could have different effects on the change in [Ca^2＋]iin the tip of pollen tube （Figs.2, 3）. The treat- ment with ＇Housui＇ stylar S-RNase could induce the decrease of fluorescence gradient of [Ca^2＋]i along the tip of self-pollen tube （Figs.2A, 3A）, and the treatment with CTX could markedly elevate [Ca^2＋]i in the tip of pollen tube showed （Fig.3C）. The way of [Ca^2＋]i changed in ‘Housui＇ pollen tube under the co-action of CTX and its stylar S-RNase showed the compositive effect of the two respec- tive treatment （Fig.3A, C, E）, but the effect of the co-action of PTX and ‘Kousui＇ stylar S-RNase showed increase in [Ca^2＋]i in the pollen tube in 18 min after treatment, and then decrease between 18- 36 min （Fig.3F）. These results suggest that during self or cross pollination, the control of the growth of Pyrus pyrifolia pollen tube is by the synergistic effect of stylar S-RNase, G protein and [Ca^2＋]i in the pollen tube.

关 键 词：G蛋白调节剂 花柱S-核糖核酸酶 花粉管 Ca^2+信号 

分 类 号：S661.2[农业科学—果树学]