烤烟K326接种野火病菌后游离氨基酸动态的研究

 烤烟K326幼苗接种野火病菌后,各类及各种能组成蛋白质的游离氨基酸的含量均明显升高,除蛋氨酸的增值峰期在发病初期外,其余均在潜育期,它们的增值量也随病程增进而递减,到发病盛期时绝大多数都低于对照。苯丙氨酸与抗性关系最密切,迅猛增值在潜育期,但消减也快,发病初期就低于对照;脯氨酸、酪氨酸、赖氨酸与抗性关系也很密切,它们迅速增量在潜育期,但消减较慢;苏氨酸、丝氨酸、亮氨酸、异亮氨酸等与抗性较为间接的氨基酸增值量仅在潜育期,随后下降低于对照,但均高于侵入期时的含量;丙氨酸、天冬氨酸、甘氨酸、缬氨酸等也与抗性有关,故含量在潜育期快速上升,增值维持到发病初期,到发病盛期时才低于对照,但其值也高于侵入期。在拮抗野火病菌的过程中精氨酸含量的变化比较奇特,它仅在潜育期时高于对照,其余时期明显低于对照;接种后,由于野火毒素干扰了蛋氨酸与谷氨酸的代谢,其二者含量明显下降。苏氨酸与丝氨酸参与野火酸（野火毒素的活性部位）的组成,所以二者除潜育期稍高于对照外,其余时期均低于对照。

Study on Free Amino Acids Dynamic in Flue-cured Tobacco K326 Seedlings after Inoculated with the Pseudomonas syringae pv. tabaci

After being inoculated with Pseudomonas tobaci Wolf ect , the free amino acids in the seedlings of flue-cured tobacco K326 increased obviously, and the peaks for all increasing free amino acids were in incubation period with the exception of methionine which was in the early stage of infection. As the infection progressed, the increasing of free amino acids slowed and at the outbreak period, the content of most of these amino acids were lower than that of the control. The level of phenylalanine was closely linked with the resistance, it increased rapidly at the incubation stage and then quickly declined. The level of proline, tyrosine and lysine also showed close relationship with the resistance, they increased rapidly at incubation stage but slowly decreased after that period. The level of threonine, serine, leucine and isoleucine were indirectly linked with the resistance, they increased only at incubation and then decreased but they were still higher than the level at the beginning of the attacking. The level of alanine, aspartic acid, glycine and valine was also related to the resistance, their concentration increased rapidly at incubation and maintained that level till the early stage of outbreak, and lowed at full outbreak stage. Changes on the level of arginine were rather unique, it was higher than that of the control only at incubation stage, and remained quite low in the rest of the time. The level of methionine and glutami acid decreased obviously due to the wild fire toxin interfered the metabolism of these two amino acids after the inoculation. Because the threonine and serine participated the formation of active ingredient of wild fire toxin, so the level of these 2 amino acids remained lower than that of the control with the exception of being a little higher at incubation stage.