| 摘要: |
| PWWP结构域蛋白是一类广泛存在于真核生物中的表观遗传调控因子，在转录调控、DNA修复和染色质重塑等方面发挥着重要作用。最新研究表明，PWWP家族成员与植物应对盐胁迫密切相关。为探究甘蓝型油菜（Brassica napus L.）中PWWP结构域蛋白家族的序列特征、进化关系及该家族如何响应盐胁迫，该研究利用生物信息学方法对该家族成员进行全基因组鉴定，分析其染色体定位、蛋白质理化性质、系统进化、保守基序、顺式作用元件、共线性，并采用实时荧光定量PCR（qRT-PCR）方法检测120 mmol·L?1 NaCl处理后种子萌发过程中各成员的表达量变化。结果表明：（1）甘蓝型油菜中共发现43个PWWP家族成员，其中22个位于A基因组上，记作BnaPWWP1-BnaPWWP22，另外21个位于C基因组上，记作BnaPWWP23-BnaPWWP43。（2）编码蛋白的氨基酸数目为177~1383，分子量为19 688.44~149 901.99 Da，等电点pI为4.7~10.01，均为亲水性蛋白，88.27%定位于细胞核。（3）系统发生树显示甘蓝型油菜、拟南芥、甘蓝以及白菜中的PWWP家族成员可以分为7个亚家族，且同亚族成员在保守基序、保守结构域及基因结构上表现出高度相似性。（4）启动子顺式作用元件分析共鉴定出29种顺式元件，其中22类分属生长发育、植物激素和非生物胁迫响应，ARE、ABRE、CGTCA-motif和TGACG-motif为出现频次最高、覆盖基因最广的核心元件。（5）盐胁迫下，5个PWWP家族成员表达量显著增加，其中BnaPWWP10、BnaPWWP11、BnaPWWP24上调显著，且其启动子区富含盐胁迫相关顺式作用元件。综上所述，该研究系统分析了BnaPWWP基因家族，发现了在甘蓝型油菜种子萌发时参与盐胁迫响应的若干BnaPWWP基因，为进一步研究BnaPWWP基因在油菜应对盐胁迫中的功能奠定了基础。 |
| 关键词: 甘蓝型油菜，PWWP基因家族，生物信息学分析，盐胁迫，表达分析 |
| DOI：10.11931/guihaia.gxzw202604014 |
| 分类号: |
| 基金项目:国家自然科学基金面上项目（31971834）；国家重点研发计划项目子课题（2022YFD1200400-3）；湖南省教育厅科学研究重点项目（25A0222）。 |
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| Genome-wide identification of the PWWP gene family and its response to salt stress in Brassica napus |
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LIU Lanxi1,2, CHEN Jin1,2, LIU Boyu1,2*
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1. College of Bioscience and Biotechnology, Hunan Agricultural University, Key Laboratory of Crop Epigenetic Regulation and Development in Hunan Province, Changsha 410128, China; 2. Yuelushan Laboratory, Changsha 410128, China
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| Abstract: |
| PWWP domain proteins are epigenetic regulators widely present in eukaryotes. They play important roles in transcriptional regulation, DNA repair, and chromatin remodeling. Recent studies have shown that PWWP family members are closely associated with plant salt stress responses. To investigate the sequence characteristics, evolutionary relationships, and salt stress responses of the PWWP domain protein family in Brassica napus, this study used bioinformatics methods to identify the family members at the whole-genome level. The study analyzed their chromosomal locations, protein physicochemical properties, phylogeny, conserved motifs, cis-acting elements, and synteny. Real-time quantitative PCR (qRT-PCR) was used to detect the expression changes of all members during seed germination under 120 mmol·L?1 NaCl treatment. The results were as follows: (1) A total of 43 PWWP family members exist in Brassica napus. Among them, 22 members are located on the A genome and are designated BnaPWWP1-BnaPWWP22, while the other 21 members are located on the C genome and are designated BnaPWWP23-BnaPWWP43. (2) The encoded proteins range in length from 177 to 1 383 amino acids, with molecular weights from 19 688.44 to 149 901.99 Da and isoelectric points from 4.7 to 10.01. All proteins are hydrophilic, and 88.27% of them are predicted to localize in the nucleus. (3) A phylogenetic tree showed that the PWWP family members from Brassica napus, Arabidopsis thaliana, Brassica oleracea, and Brassica rapa can be divided into seven subfamilies. Members within the same subfamily share highly similar conserved motifs, conserved domains, and gene structures. (4) Promoter cis-acting element analysis identified 29 types of elements. Among them, 22 types are associated with growth and development, plant hormones, and abiotic stress responses. ARE, ABRE, CGTCA-motif, and TGACG-motif are the core elements with the highest frequency and the widest gene coverage. (5) Under salt stress, the expression of five PWWP family members increased significantly. Among them, BnaPWWP10, BnaPWWP11, and BnaPWWP24 are notably up-regulated, and their promoter regions are rich in salt stress-related cis-acting elements. In summary, this study systematically analyzes the BnaPWWP gene family and identifies several BnaPWWP genes that participate in the salt stress response during seed germination in Brassica napus. These findings lay a foundation for further study of the functions of BnaPWWP genes in rapeseed under salt stress. |
| Key words: Brassica napus, PWWP gene family, bioinformatics analysis, salt stress, expression analysis |
