Spd和MGBG对黄瓜子房内源多胺和蛋白质组成的影响及与单性结实的关系

Effects of Spd and MGBG on Endogenous Polyamine Levels and Protein Profiles in Ovary and Its Relationship with Parthenocarpy of Cucumber

以黄瓜(Cucum is sativusL.)单性结实品系EP-6与非单性结实品系ZR-2为试材,研究外源亚精胺(Spd)和多胺合成抑制剂MGBG处理对子房(幼果)内源多胺含量和蛋白质组成的影响及其与黄瓜单性结实和幼果发育的关系。结果表明:花前2 d对ZR-2不授粉子房施用外源亚精胺能显著提高子房内源亚精胺、精胺与腐胺水平,促进其单性结实和果实生长,而花前2 d对EP-6不授粉子房外源施用MGBG则显著降低其子房内源亚精胺和精胺水平,提高了内源腐胺水平,导致子房萎蔫。运用SDS-PAGE法研究了外源亚精胺和MGBG处理后子房中可溶性蛋白质组成的变化,结果表明:ZR-2用外源Spd处理,开花当天至花后3 d的子房中出现了分子量为55 kD与37 kD的两种特异蛋白质,花后1 d至花后3 d又出现了88 kD与82 kD两种特异蛋白质;单性结实品系EP-6用MGBG处理子房,开花当天至花后3 d出现了47 kD与25kD两种特异蛋白质,引起85 kD、45 kD与10 kD蛋白质的消失。这些结果表明,外源多胺和多胺合成抑制剂处理可能是通过改变内源多胺水平和蛋白质合成而影响单性结实和子房(幼果)发育。

The effect of spermidine and polyamine biosynthetical inhibitor-MGBG on endogenous polyamine contents and protein profiles of ovary and its correlation with cucumber parthenocarpy and ovary development were studied using parthenocarpic line EP-6 and non-parthenocarpic line ZR-2 treated with exogenous spermidine and MGBG. The results were as follows ： the exogenous applications of Spd at 1 mmol/L at 2 days before anthesis could significantly increase endogenous Spd, Spm and Put levels in the non-pollinated ovaries of ZR-2 at 2 days after anthesis, and the increasing in fruit length and fresh fruit mass could also be observed, which resuited in parthenocarpic ovary （young fruit） growth in the line ZR-2 when non-pollinated. However, the contents of Spd and Spm in the ovary of EP-6, treated with MGBG, were decreased dramatically, while the content of Put was increased. The growth of fruit length and fresh fruit mass was inhibited, which led to ovary wither. The results suggested that both Spd and Spm promote cucumber parthenocarpy and ovary （young fruit） growth. We also studied changes of specific protein profiles during ovary/young fruit development treated with exogenous Spd on ZR-2 and MGBG on EP-6. The results showed that specific proteins of 88 kD, 82 kD, 55 kD and 37 kD were identified in the ovary/young fruit of ZR-2 with exogenous Spd application. Application of polyamine biosynthesis inhibitor MGBG on EP-6 ovary could induce the biosynthesis of specific proteins of 47 kD and 25 kD, but lead to the disappearance of the proteins of 85 kD, 45 kD and 10 kD. Those results indicated that exogenous application of Spd and MGBG might stimulate ovary/young fruit growth and induce parthenocarpy by regulating endogenous Spd and Spm levels and inducing the synthesis of some specific proteins.