低温锻炼对水稻幼苗叶片中Rubisco的影响  

The Effects of Cold-hardening on Rubisco in Rice Seedling Leaves

作　　者：赵军[1] 王以柔[1] 李美茹[1] 刘鸿先[1] 缪有刚[2] 李立人[2] 

机构地区：[1]中国科学院华南植物研究所,广州510650 [2]中国科学院上海植物生理研究所,上海200032

出　　处：《植物生理学报（0257-4829)》1997年第2期123-129,共7页Acta Phytophysiologica Sinica

基　　金：国家自然科学基金

摘　　要：低温锻炼能提高水稻幼苗的抗冷力，低温锻炼虽不能明显提高Rubisoc活性，却提高了冷胁条件下Rubisoc的稳定性和增强了胁迫后正常生长条件下其活性的恢复能力。分别用火箭免疫电泳分析Rubisoc蛋白和SDS-PAGE分析大、小亚基量表明：低温锻炼未提高Rubisoc蛋白的合成能力，但增加了大、小亚基的合成量。经锻炼、冷胁迫以及恢复后Lsu／Ssu比值的变化主要是由于小亚基对温度变化更敏感所致。Rubisco酶特性分析表明，低温锻炼有减少水稻幼苗Rubisoc表面的SH数，并提高Rubisco蛋白在高、低温下的稳定性。The changes in activity, proteincontent and character of Rubisco inleaves caused by cold-hardening andchilling stress were studied. The coldhardening at 14 ℃ and under a PFD of75 μmol m-2 s-1 during daytime for 3days reduced the death rate of riceseedlings caused by a chilling stress at1℃ and under a PFD of 160 μmol m- 2s-1 for 2 days(Fig. 1 ), indicating thatcold-hardening increases chilling tolerance. The Rubisco activity in hardenedseedlings(HS) was similar to that in unhardened seedlings (UHS) (Fig. ZA ).However, after 2 days of chilling stress(Fig. 2B), the activities of both HS andUHS decreased. Futhermore, whenboth HS and UHS were put back to normal condition for recovery, the activityof HS could recover to the level of thecontrol of the same age, while that ofUHS remained lower (Fig. 2C). Theseresults showed that cold-hardening increased also the stability of the Rubiscounder chilling temperature. By rocketimmunoelectrophoresis test, it indicatedthat the changes of Rubisco protein content caused by cold-hardening and chilling stress ran parallel with, but not exactly proportional to the change in activity (Figs. 2, 3), changes of the activity (Fig. 2B,C) indicating that the specific activity of Rubisco had changedtoo. Cold-hardening could increase thesynthesis of Lsu and Ssu (Fig. 4A, A 1 ),but not the Rubisco protein content, indicating that cold-hardening did notpromote the assembling of the enzyme.The change of the Lsu/Ssu ratio showedthat Ssu was more sensitive to low temPerature than Lsu (Fig. 4B2, C2 ). ByDTNB modification of the surface SHgroups, it was found that the number ofsurface SH groups of Rubisco from HSwas 10% lower than that of UHS(Table 1 ), the Rubisco protein contentfrom HS was more stable than that ofUHS under both high and low temperatures(Figs. 5- 7). From the above results, it is suggested that the increase ofcold tolerance by cold-hardening in riceseedlings is associated with the changein Rubisco character.

关 键 词：低温锻炼 水稻 幼苗 核酮糖 二磷酸羧化酶 

分 类 号：S511.01[农业科学—作物学]