中国农业科学2009，Vol.42Issue(12)：4209-4217,9.DOI:10.3864/j.issn.0578-1752.2009.12.011
Ca~(2+)和Ca~(2+)-ATPase在小麦颖果筛分子分化中的动态变化
Dynamic Changes of Ca~(2+) and Ca~(2+)-ATPase in Sieve Elements in the Developing Caryopsis of Triticum aestivum L.
摘要
Abstract
[Objective] Previous study revealed that sieve elements (SEs) in the developing caryopsis of Triticum aestivum L.underwent a unique type of programmed cell death (PCD).In this paper,the dynamic changes and the roles of Ca~(2+) and Ca~(2+)-ATPase in SEs during the PCD were studied.[Method] The ultrastructural aspects of phloem cells in wheat caryopsis were examined by transmission electron microscopy (TEM).Using specific fluorescence staining and potassium pyroantimonate precipitation method,Ca~(2+) was localized at histological and sub-cellular levels in SEs in the developing wheat caryopsis.TEM and lead nitrate were used to locate Ca~(2+)-ATPase in SEs.[Result] TEM studies showed that the cell walls of SEs thickened at the beginning of differentiation,and then became thinner and smoother.Fluorescence staining showed that the fluorescence due to Ca~(2+) appeared in cell walls of SEs from 6 to 10 d after flowering.The fluorescence due to Ca~(2+) in cell walls of SEs was most notable on 9 d after flowering and disappeared on 14 d after flowering.Sub-celluar localization of Ca~(2+) showed that Ca~(2+) was localized on plasma membrane and in nuclei from 1 to 2 d after flowering.On 4 d after flowering,Ca2+ was localized in cytoplasm and mitochondria of SEs.From 5 to 8 d after flowering,Ca~(2+) was transported to the cell walls of SEs and no Ca~(2+) precipitates were observed in mitochondria.From 10 to 18 d after flowering,Ca~(2+) was transported into the cytoplasm again from cell walls and no Ca~(2+) precipitates were observed on 20 d after flowering.In intermediary cells (ICs),Ca~(2+) precipitates were observed from 1 to 18 d after flowering,and Ca~(2+) mainly distributed on intine and tonoplast.The activity of Ca~(2+)-ATPase changed obviously during the SEs differentiation.There was lowest activity of Ca~(2+)-ATPase on 3 d after flowering in SEs.High levels of Ca~(2+)-ATPase activity were found from 4 to 14 d after flowering in SEs,and the enzyme was mainly localized in cell walls,cytoplasm,plasmodesmata,mitochondria and nuclei.[Conclusion]These results showed the dynamic changes of Ca~(2+) and Ca~(2+)-ATPase in SEs differentiation.Ca~(2+) might play important roles in SEs during the PCD.In addition,Ca~(2+) and Ca~(2+)-ATPase might be also related to cell wall thickening and functions of SEs.关键词
小麦(Triticum aestivum L.)/颖果/筛分子/Ca~(2+)/Ca~(2+)-ATPaseKey words
wheat (Triticum aestivum L.)/caryopsis/sieve elements/Ca~(2+)/Ca~(2+)-ATPase分类
农业科技引用本文复制引用
李继伟,邓祥宜,周竹青,王利凯,阳超男,樊海燕..Ca~(2+)和Ca~(2+)-ATPase在小麦颖果筛分子分化中的动态变化[J].中国农业科学,2009,42(12):4209-4217,9.基金项目
国家自然科学基金项目(30571101) （30571101）
