在条锈菌侵染早期小麦初生叶内多聚核糖体水平与蛋白质合成能力的变化

Changes in Polyribosome Level and Protein Synthesis of Wheat Leaves in the Early Stage of Stripe-Rust Infectal

小麦初生叶接种条锈菌毒性生理小种（ＣＹ２９）及其弱毒突变菌系（ＣＹ２９－ｍｕｔ３）后，呈不亲和反应的寄主叶片可溶性蛋白质合成能力在接种后２４ｈ显著高于未接种对照，但其后逐渐降低，直至接近对照；而呈亲和性反应的寄主叶片可溶性蛋白质合成在侵染早期与对照相近，但与膜结合蛋白质在９６ｈ时大大高于对照。对接种叶中核糖体的密度梯度分析证实：呈不亲和反应寄主叶片游离多聚核糖体及亲和反应的寄主内与膜结合多聚核糖体均有特异性增加。上述结果表明寄主的抗病和感病反应均与蛋白质合成能力的变化有关。

After wheat (Triticum aestivum L. CV Lovrin 13) primary leaves inoculated with virulent race (CY29 ) of stripe-rust fungus (Puccinia striiformis West)and its avirulent mutunt (CY29--mut3), the rate of soluble protein synthesis in vivo in incompatible host leaves was higher than uninoculated leaves 24 h after inoculation,and then declined. In compatible host leaves, however, though soluble protein synthesis was the same as uninoculated leaves during the early sarge of infection, a sharp increase in the rate of synthesis of membrane bound protein occurred 96 h after inoculation.Meanwhile, analysis of ribosome in wheat primary leaves by sucrose density gradient centrifugation confirmed that there was predominant increase of free polyribosome level in incompatible host and of membtane bound polyribosome level in compatible hod. It is conclued that reactions of both the resistant and susceptible host plants involve alterations in protein synthesis ability .