盐胁迫对坪山柚、福橘幼苗叶片蛋白质合成的影响

Effects of salt stress on the protein synthesis in seedlings of Citrus grandis Osbeck and C.reticulata Blanco

以坪山柚和福橘幼苗为材料,研究不同浓度NaC l胁迫8 d后叶片中可溶性蛋白质的变化.结果表明,盐胁迫下,坪山柚和福橘幼苗叶片中可溶性蛋白质含量增加并随NaC l浓度的增高而增至较高水平.相同浓度NaC l胁迫下,坪山柚叶片可溶性蛋白质含量增加幅度比福橘大,因此,可能是蛋白质的增加幅度而不是其绝对含量对坪山柚的耐盐性起作用.十二烷基硫酸钠-聚丙烯酰胺凝胶电泳十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)图谱分析显示,盐胁迫后,分子质量为80、67、54、32、28、18、17和16 ku蛋白质不受影响而稳定表达.福橘叶片中80、67、32、28、21、18、17、16和15 ku蛋白质为稳定表达的蛋白质.当NaC l浓度≥40 mmol.L-1时,诱导坪山柚叶片新产生35和24 ku 2种蛋白质;当NaC l浓度≥80 mmol.L-1时,诱导福橘叶片新产生72、43和24 ku 3种蛋白质,且它们的活性均随盐胁迫强度的增大而增强.

Changes of soluble protein in leaves of Citrus grandis Osbeck cv. Pingshanyou and C. reticulata Blanco cv. Fuju seedhngs were studied under different NaCl concentration stress for eight days. The results showed that the contents of soluble protein in leaves of Pingshanyou and Fuju seedlings increased under NaCl stress, and the contents reached a higher level with the increase in the concentration of NaCl. The increment of soluble protein in Pingshanyou leaves was higher than in Fuju under the same NaCl concentration stress. So it is the increment but not the absolute content of soluble protein took a role on the salt tolerance of Pingshanyou. Sodium dodecyl sulfate polyacrylamide gel electrophoresis （SDS-PAGE） analysis indicated that the 80, 67, 54, 32, 28, 18, 17 and 16 ku proteins were unaffected by NaCl stress and expressed stably in leaves of Pingshanyou seedlings; the 80, 67, 32, 28, 21, 18, 17, 16 and 15 ku proteins were the stably expressed proteins in Fuju. 35 and 24 ku proteins were newly induced as specific protein in Pingshanyou leaves when they were treated with 〉 40 mmol · L^-1 NaCl, while 72, 43 and 24 ku proteins were induced in Fuju＇s when they were treated with 〉 80 mmol· L^-1 NaCl. The activities of all these newly induced specific proteins increased with the NaCl concentration.