生物炭对烤烟质体色素代谢的影响

摘要

To reveal the influence mechanism of biochar on the plastid pigment metabolism in flue-cured tobacco, the cell structure, gene expression and substance metabolism of cv. K326 were studied. Cell ultrastructure analysis indicated that: at the early mature stage of middle leaves, the thylakoid lamellae content in leaves treated by biochar application rate of 300 or 600 kg/ha was higher and decreased along with the development of tobacco leaves, and it decreased more obviously in the leaves without biochar application (the control). Gene expression analysis showed that: the expression of genes related to plastid pigment synthesis reduced gradually, while the expression of genes related to plastid pigment degradation increased after topping; and the expression of genes related to carotenoid biosynthesis and degradation was relatively stronger by biochar treatement at the rate of 300 or 600 kg/ha. Substance metabolism analysis suggested that: the plastid pigment content in leaves reduced gradually after topping; biochar application increased the plastid pigment accumulation in leaves. At the later stage of middle leaf maturing, the plastid pigment accumulation reached the highest in leaves treated by biochar at the rate of 300 kg/ha, while it decreased and was close to that in the control with the increase of biochar application rate. The contents of pigment degradation products and neutral aroma components in cured leaves treated by biochar at the rate of 300 kg/ha were the highest, while those in leaves without applying biochar were the lowest. Therefore, applying biochar at an appropriate rate is beneficial to the pigment metabolism in leaves at mature stage and the formation of neutral aroma components in cured leaves.%为揭示生物炭对烤烟质体色素代谢的影响机理,以烤烟品种K326为材料,从细胞组织结构、基因表达以及物质代谢三个层面进行了研究.细胞超微结构分析表明:中部叶成熟早期,添加300和600 kg/hm2生物炭烟叶类囊体片层数量较多,随着叶片成熟类囊体片层数量减少,不施用生物炭的对照烟叶类囊体片层数量减少更明显.基因表达分析显示:打顶后色素合成相关基因的表达逐渐减弱,色素降解相关基因的表达增强;添加300和600 kg/hm2生物炭,烟叶类胡萝卜素合成及降解相关基因表达相对较强.物质代谢分析表明:打顶后烟叶色素含量(质量分数)逐渐降低;添加生物炭后色素积累较多.中部叶成熟后期,添加300 kg/hm2生物炭的处理烟叶色素积累最多,随生物炭施用量的增加,烟叶色素积累减少并接近对照.添加300 kg/hm2生物炭的处理调制后烟叶色素降解产物及中性致香物质总量最高,而不施用生物炭的处理最低.因此,施用适量生物炭有利于成熟期烟叶色素的代谢及调制后烟叶中性致香物质的形成.