近日，中科院植物研究所马庆虎研究组通过对木质素代谢与基因表达分析，揭示了木质素合成与小麦抗倒伏之间的关系，并定位了与抗倒伏相关的木质素基因。该成果发表在Journal of Experimental Botany（2009, 60: 2763–2771）杂志上。
小麦的倒伏是影响其稳产高产的一个重要因素。倒伏是一个由生理、遗传、栽培和环境等多因素调控的数量性状，对其分子水平的调控机理尚需要深入的研究。在农业生产上，通过矮化基因的开发和育种曾经有效地缓解了小麦倒伏危害的发生，但是随着株高的降低会影响小麦生物产量的潜力，因此通过增强茎秆强度，在不降低株高的情况下提高小麦的抗倒伏特性对开发高产小麦具有重要意义。木质素是植物细胞壁中起机械支持的重要高分子物质。马庆虎研究组分离了在小麦茎秆中高度表达的木质素合成关键酶基因—咖啡酸甲基转移酶基因（COMT），通过生化和转基因分析证明COMT 在控制松柏醇型木质素上发挥着重要作用，COMT基因的表达在抗倒伏小麦生长发育后期明显高于易倒伏品种，这种基因的高表达进一步促进了COMT酶蛋白和酶活力的提高，并增强了木质素的合成。小麦的COMT基因定位在3B染色体上。
该研究成果对阐明木质素代谢与倒伏关系，并通过调控木质素代谢培育抗倒伏的高产超级小麦具有重要意义。（生物谷Bioon.com）
生物谷推荐原始出处：
Journal of Experimental Botany 2009 60(9):2763-2771; doi:10.1093/jxb/erp132
The expression of caffeic acid 3-O-methyltransferase in two wheat genotypes differing in lodging resistance
Qing-Hu Ma*
Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, 20 Nanxin Cun, Xiangshan, Beijing 100093, China
Stem lodging-resistance is an important phenotype in crop production. In the present study, the expression of the wheat COMT gene (TaCM) was determined in basal second internodes of lodging-resistant (H4564) and lodging-susceptible (C6001) cultivars at stem elongation, heading, and milky endosperm corresponding to Zadoks stages Z37, Z60, and Z75, respectively. The TaCM protein levels were analysed by protein gel blot and COMT enzyme activity was determined during the same stem developmental stages. TaCM mRNA levels were higher in H4546 from elongation to the milky stages and in C6001 the TaCM mRNA levels decreased markedly at the heading and milky stages. The TaCM protein levels and COMT activity were also higher in H4564 than that in C6001 at the heading and milky stages. These results corresponded to a higher lignin content measured by the Klason method and stem strength and a lower lodging index in H4564 than in C6001 at the heading and milky stages. Therefore, the TaCM mRNA levels, protein levels, and enzyme activity in developing wheat stems were associated with stem strength and lodging index in these two wheat cultivars. Southern analysis in a different population suggested that a TaCM locus was located in the distal region of chromosome 3BL, which has less investigated by QTL for lodging-resistant phenotype.
