银杏种子发育过程中胚乳内含物的变化

Changes of endosperm inclusions during the development of Ginkgo biloba seeds

本研究围绕银杏种子发育的全过程,探究胚乳内含物质动态变化规律,测定了不同发育时期胚乳内可溶性糖、淀粉、蛋白质的含量变化与淀粉酶、磷酸己糖异构酶(PGI)、葡萄糖-6-磷酸脱氢酶(G-6-PDH)和6-磷酸葡萄糖脱氢酶(6-PGDH)联合酶、苹果酸脱氢酶(MDH)活性,旨在为银杏胚胎学研究提供一定的理论参考。结果表明:在种子发育早期(花后40~120 d),胚乳的淀粉、可溶性糖和蛋白质的含量逐渐增加,糖酵解途径(EMP)首先被激活;在受精及胚分化过程中(花后120~160 d),戊糖磷酸途径(PPP)途径活化程度不断推进并维持在较高水平,MDH活性在胚分化完成时达到高峰,三羧酸循环为胚分化发育提供了能量。在胚胎发育后期(花后170~190 d),a-淀粉酶活性持续升高,表明a-淀粉酶可能对后期胚发育具有一定的调节作用。淀粉处于不断累积和被利用,参与了胚胎发育的代谢过程。

This study focuses on the whole process of Ginkgo seed development,and explored the dynamic changes of endosperm inclusions.The contents of soluble sugar,starch and protein and the activity of phosphoglucose isomerase(PGI),combined glucose-6-phosphate dehydrogenase(G-6-PDH)and 6-phosphogluconate dehydrogenase(6-PGDH),malate dehydrogenase(MDH)in endosperm of different developmental stages were determined.The aim was to provide a theoretical reference for the embryology research of Ginkgo biloba.Result showed that the content of starch,soluble sugar and protein in the endosperm increased gradually during early seed development(40-120 d),and the glycolytic pathway(EMP)was occurred first;During fertilization and embryo differentiation(120-160 d),the activation of the pentose phosphate pathway(PPP)was continuously promoted and maintained at a high level.The MDH activity reached its peak at the completion of embryo differentiation,indicating that the TCA cycle provides energy for embryo development.In the late embryo stage(170-190 d),α-amylase activity continued to increase,indicating thatα-amylase may have a regulatory effect on embryo development.Starch was accumulated and consumed continuously,which is involved in the metabolic process of embryo development.