【作者】 周； 王玉峰； 娄来清； 周华； 陈素丽； 蔡庆生； 滕胜；

【Author】 ZHOU Yan~(1,2) WANG Yufeng~2 LOU Laiqing~1 ZHOU Hua~2 CHEN Suli~2 CAI Qingsheng~(1*) TENG Sheng~(2*) 1.College of Life Sciences,Nanjing Agricultural University,Nanjing 210095,China 2.Institute of Plant Physiology and Ecology,SIBS,CAS,Shanghai 200032,China

【机构】 南京农业大学生命科学学院； 中国科学院植物生理生态研究所；

【摘要】 生长快、生物量高的甜高粱具有作为可再生能源作物的应用潜力,适当改变植物木质素合成总量,将有利于能源转化效率的提高。本研究以木质素合成途径中关键的限速酶——4-香豆酸辅酶A连接酶(4-coumarate:CoA ligase,4CL)为研究对象,通过在NCBI数据库中对植物中4CL蛋白同源序列分析,发现高梁中有7个4CL-like蛋白。以甜高粱大力士品种的eDNA为模版,成功克隆到了其全部的基因序列。序列对位排列分析显示,甜高粱这7个4CL-like基因在高粱属中非常保守,其编码的氨基酸序列与水稻中相对应的4CL有90%左右相似度,因此这7个4CL-like蛋白应属于甜高粱的4CL家族,并且它们可分为4CL ClassⅠ和4CL ClassⅡ两类,其中Sb07G007810、Sb04G005210、Sb10G026130、Sb07G022040、Sb03G000610和Sb06G016630属于4CL Classl,Sb04G031010属于4CL ClassⅡ。这7个蛋白均可利用原核表达系统实现高表达。通过对甜高粱这7个4CL基因时空表达分析可知,作为木质素合成的4CL ClassⅠ类基因在组织生长快速期的表达量非常高,而作为类黄酮合成的4CL ClassⅡ类基因在植物受到太阳直接照射的部位表达量有显著地升高。Sb04G005210基因为根和茎中主效的4CLClassⅠ基因,Sb07G007810基因和Sb04G005210基因则属于叶中主效4CL ClassⅠ基因。本研究为进一步挖掘和创造适合高能转化的甜高梁种质资源奠定了基础。更多还原

【Abstract】 Sweet Sorghum is a potential energy plant due to its abilities of fast growth and high biomass.It is beneficial to improve the efficiency of energy transformation by controlling lignin contents in plants.4-coumaric acid coenzyme A ligase(4CL) is a key rate-limiting enzyme in the biosynthesis of lignin.Seven 4CL-like proteins in sorghum were found by homolog blast in NCBI plant database.Taking cDNA of sweet sorghum varieties as the template,we have successfully cloned the seven 4CL-like gene sequences.It was found that seven 4CL-like proteins from sweet sorghum were highly conserved in Sorghum by sequence alignment and bioinformatic analysis,and were 90%similarity to corresponding 4CL proteins in rice.They belong to 4CL ClassⅠand 4CL ClassⅡtypes,respectively,and ClassⅠincluding Sb7G007810,Sb4G005210,Sb10G026130,Sb07G022040,Sb03G000610 and Sb06G016630,ClassⅡincluding Sb4G031010.These seven proteins can achieve high expression using prokaryotic expression system..The results showed that the ClassⅠ4CL gene, which take part in the lignin biosynthesis,have highly expression in plant fast-growing stage. However,the ClassⅡ4CL gene,which participate in flavonoid synthesis,show significantly increased expression in the parts which receive solar radiation derectly.During ClassⅠ4CL genes,Sb04G005210 is the dominant gene in sweet sorghum root and stem,and Sb07G007810 and Sb04G005210 are dominant in sweet sorghum leaf.This study lays a solid foundation for mining and creating new sweet sorghum germplasm with efficient energy conversion.更多还原