摘要
剑麻是热带地区重要的纤维作物,但其分子生物学研究基础薄弱,纤维发育机制尚未明确。苯丙氨酸裂解酶(phenylalanine ammonia-lyase,PAL)是纤维重要组分木质素生物合成的起始酶,近年来转录组测序技术快速发展,使开展剑麻PAL基因相关研究更为便利。本文根据已报道转录组数据成功鉴定出2个含完整编码序列的剑麻PAL基因,其在剑麻叶片发育过程中的表达模式与前人报道的PAL在纤维发育过程中的活性变化规律一致,表明其与木质素生物合成密切相关。遗传进化分析结果显示,剑麻和番麻PAL基因进化关系更近,选择压力分析结果显示,剑麻和番麻PAL基因序列选择压力一致且高于太匮龙舌兰PAL基因,这一现象可能由剑麻和番麻纤维性状的趋同进化引起。此外,剑麻PAL基因在铜铅胁迫后差异表达不显著,其可能在重金属胁迫后受到转录后调控。值得一提的是,在烟草疫霉侵染后,剑麻PAL基因表达水平上调倍数较高,其可能同时参与苯丙烷类代谢途径中抗病相关次生代谢产物的合成和细胞壁介导的免疫机制。因此开展剑麻PAL基因功能解析可加深对剑麻纤维发育机制和抗病机制的理解,对培育高产、优质、多抗剑麻新品种具有重要意义。
Sisal is an important fiber crop in tropical areas,but its research foundation of molecular biology is relatively weak,and the mechanism of fiber development still remains unclear.Phenylalanine ammonia-lyase(PAL)is the first enzyme of lignin bio-synthesis,which is an important component of fiber.According to published transcriptome data,two sisal PAL genes with complete coding sequences were successfully identified.Their expression patterns during sisal leaf development were consistent with previously reported PAL activity changes during fiber development,indicating that PAL was closely related to lignin bio-synthesis.Phylogenetic analysis showed that sisal PALs were closely related with Agave americana.Selection pressure analysis showed similar selection pressure of PALs in sisal and A.americana,which were higher than those in A.tequilana.This might be caused by the convergent evolution of fiber-related traits in sisal and A.americana.In addition,sisal PALs were not significantly expressed under neither copper nor lead stress,which might be caused by post-transcriptional regulation under heavy metal stresses.It was worth noting that the expression of sisal PALs was highly up-regulated after Phytophthora nicotianae Breda inoculation.Sisal PALs might participate in the bio-synthesis of disease resistance-related secondary metabolites in phenylpropanoid pathway,as well as plant cell-wall mediated immunity.Therefore,functional characterization of sisal PALs could improve the understanding of mechanisms in fiber development and disease resistance,which is of great importance for breeding new sisal varieties with high yield,high quality and multiple resistance.
作者
黄兴
习金根
陈涛
覃旭
谭施北
陈河龙
易克贤
HUANG Xing;XI Jin-Gen;CHEN Tao;QIN Xu;TAN Shi-Bei;CHEN He-Long;YI Ke-Xian(Environment and Plant Protection Institute,Chinese Academy of Tropical Agricultural Sciences/Key Laboratory of Integrated Pest Management on Tropical Crops,Ministry of Agriculture and Rural Affairs/Hainan Key Laboratory for Monitoring and Control of Tropical Agricultural Pests,Haikou 571101,Hainan,China;Guangxi Subtropical Crops Research Institute,Nanning 530001,Guangxi,China;Institute of Tropical Bioscience and Biotechnology,Chinese Academy of Tropical Agricultural Sciences,Haikou 571101,Hainan,China)
出处
《作物学报》
CAS
CSCD
北大核心
2021年第6期1082-1089,共8页
Acta Agronomica Sinica
基金
国家重点研发计划项目(2018YFD0201100)
国家现代农业产业技术体系建设专项(CARS-16)
海南省自然科学基金项目(319QN275,320RC698)
广西重点研发计划项目(桂科AB18221105)
“一带一路”热带项目(BARTP-08)资助。
