摘要
脂肪酸去饱和酶(FAD)通过催化脂肪酸酰基链双键形成调控不饱和脂肪酸合成,在植物生长发育及逆境响应中发挥重要作用。为解析高梁FAD基因家族的分子特征,基于水稻20个FAD蛋白序列,采用Blastp与隐马尔可夫模型(HMM)联合筛选,从高梁基因组中鉴定出24个SbFAD基因家族成员,并系统开展生物信息学分析。结果表明,24个SbFAD基因不均匀分布于9条染色体上,其中,第1、2、4号染色体分布密度最高(各含4个成员);蛋白理化特性分析表明,SbFAD蛋白氨基酸残基数为325~480个,理论等电点(pI)为5.26~9.33,多数呈亲水性;系统进化分析结果揭示,SbFAD蛋白与水稻同源基因高度保守,且同一亚家族成员具有相似的保守基序;基因结构呈现显著差异,外显子数量2~10个,其中,SbFAD21含10个外显子;所有成员蛋白均含典型FAD结构域,SbFAD06、SbFAD09额外携带细胞色素b5(Cyt-b5)结构域;亚细胞定位预测结果显示,主要定位于叶绿体与质膜,二级结构以α-螺旋和无规则卷曲为主;基因复制分析结果提示,片段重复事件参与家族扩增,且与玉米、水稻FADs呈现高度同源;启动子区富集激素响应、非生物胁迫及发育相关顺式作用元件;表达谱分析结果显示,热图聚类Ⅰ的6个成员在高梁全生育期及多组织中广泛表达。文章系统阐明了高梁FAD基因家族进化特征与功能分化模式。
Fatty acid desaturases(FADs)play an important role in plant growth,development,and stress response by catalyzing the formation of double bonds in fatty acid acyl chains to regulate unsaturated fatty acid synthesis.To analyze the molecular characteristics of the FAD gene family in sorghum,in this study,a combined screening strategy of Blastp and Hidden Markov Model(HMM)was used based on 20 FAD protein sequences in rice to identify 24 SbFAD gene family members from the sorghum genome,and bioinformatics analysis was systematically conducted.The research results showed that 24 SbFAD genes were unevenly distributed on 9 chromosomes,with the highest distribution density on chromosomes 1,2,and 4(each containing 4 members).The analysis of protein physicochemical properties showed that the number of amino acid residues in SbFAD protein ranged from 325 to 480,with a theoretical isoelectric point(pI)of 5.26-9.33,and most of them were hydrophilic.Systematic evolutionary analysis revealed that SbFAD protein was highly conserved with rice homologous genes,and members of the same subfamily had similar conserved motif compositions.The gene structure showed significant differences,with a range of 2-10 exons,among which SbFAD21 contained 10 exons.All members contained typical fatty acid desaturase domains,with SbFAD06/SbFAD09 carrying an additional cytochrome b5(Cyt-b5)domain.Subcellular localization prediction showed that it was mainly located in chloroplasts and plasma membranes,with secondary structures mainly consisting of alpha helixes and random coils.Gene replication analysis suggested that fragment duplication events were involved in family amplification and highly homologous to FADs in maize and rice.The promoter region was enriched with hormone responsive,abiotic stress,and developmental related cis acting elements.Expression profiling analysis showed that six members of Heatmap clusteringⅠwere widely expressed throughout the entire growth period and multiple tissues of sorghum.This study provided a systematic elucidation of the evolutionary characteristics and functional differentiation patterns of the sorghum FAD gene family.
作者
张晓春
王要闯
刘平丽
徐玲
王凤宇
高珂珂
王军凤
王栋
宋军锋
ZHANG Xiaochun;WANG Yaochuang;LIU Pingli;XU Ling;WANG Fengyu;GAO Keke;WANG Junfeng;WANG Dong;SONG Junfeng(Hebi Academy of Agricultural Sciences,Hebi 458030,China;Hebi City Bureau of Agriculture and Rural Affairs,Hebi 458030,China;Henan Modern Seed Industry Co.,Ltd.,Zhengzhou 450000,China;Sinograin Zhumadian Depot Co.,Ltd.,Zhumadian 463000,China)
出处
《山西农业科学》
2026年第1期39-52,共14页
Journal of Shanxi Agricultural Sciences
基金
2024年鹤壁市重大创新专项。
