抗倒伏甘蓝型油菜(Brassica napus L.)木质素含量及木质素合成关键基因的表达

摘要

To compare the difference of lignin content and expression of key genes in lignin biosynthesis between lodging-resistant lines and susceptible lines in Brassica napus L. , lignin contents in roots, root collars and stems of 6 lodging-resistant lines and 5 susceptible lines were measured during bolting and flowering periods, and cDNA fragments of the 3 critical genes ( COMT, F5H and 4CL) related to lignin biosynthesis were amplified by RT-PCR using primers designed from the conservative region of existing gene sequences. The results were follows; At bolting stage, lignin contents in root collars and stems of lodging-resistant lines were 0.95 and 1.90 percentage points more than those in susceptible lines, respectively. But at flowering stage, lignin contents in roots, root collars and stems of lodging-resistant lines were 2. 53, 1. 97 and1.58 percentage points more than those in susceptible lines, respectively. At bolting and flowering stages, the expression levels of COMT gene in roots, root collars and stems were similar between lodging-resistant lines and susceptible lines. Expression levels of F5H gene of lodging-resistant lines in roots and stems at bolting and in roots at flowering were higher than those in susceptible lines. At bolting and flowering, expression levels of 4CL gene of lodging-resistant lines in roots and root collars were significantly higher than those of susceptible lines, but the levels in stems were not significantly different. It indicated that lodging-resistant lines could accumulate more lignin than susceptible lines during bolting and flowering periods. F5H and 4CL genes might be key genes related to lodging resistance in Brassica napus L.%测定了甘蓝型油菜6个抗倒伏材料和5个易倒伏材料薹期和花期植株不同部位的木质素含量，并对木质素合成关键酶基因F5H(阿魏酸-5-羟基化酶)基因、4CL(4-香豆酸辅酶A连接酶)基因、COMT(咖啡酸/5-羟基阿魏酸-O-甲基转移酶)基因进行RT-PCR扩增，以分析抗倒伏和易倒伏材料间木质素含量的差异以及上述3个与木质素合成相关的关键酶基因的表达差异。结果显示：薹期根颈和茎部木质素含量，抗倒伏材料比易倒伏材料分别高0.95个百分点和1.90个百分点；开花期根、根颈和茎部木质素含量，抗倒伏材料比易倒伏材料分别高2.53个百分点、1.97个百分点和1.58个百分点；COMT基因在薹期和开花期的根、根颈和茎部的表达量，抗倒伏与易倒伏材料间没有明显差异；F5H基因在薹期根、茎部和开花期根部的表达量，抗倒伏材料明显高于易倒伏材料；4CL基因在薹期和开花期根、根颈的表达量，抗倒伏材料明显高于易倒伏材料；但在薹期和开花期的茎部，抗倒伏材料与易倒伏材料间4CL基因表达量差异不显著。表明，抗倒伏材料薹期和开花期根、根颈和茎部合成的木质素含量较高，F5H和4CL基因可能是与油菜抗倒伏性状相关的关键基因。