Table4_Global Survey, Expressions and Association Analysis of CBLL Genes in Peanut.XLSX

Cystathionine γ-synthase (CGS), methionine γ-lyase (MGL), cystathionine β-lyase (CBL) and cystathionine γ-lyase (CGL) share the Cys_Met_Meta_PP domain and play important roles in plant stress response and development. In this study, we defined the genes containing the Cys_Met_Meta_PP domain (PF01053.20) as CBL-like genes (CBLL). Twenty-nine CBLL genes were identified in the peanut genome, including 12 from cultivated peanut and 17 from wild species. These genes were distributed unevenly at the ends of different chromosomes. Evolution, gene structure, and motif analysis revealed that CBLL proteins were composed of five different evolutionary branches. Chromosome distribution pattern and synteny analysis strongly indicated that whole-genome duplication (allopolyploidization) contributed to the expansion of CBLL genes. Comparative genomics analysis showed that there were three common collinear CBLL gene pairs among peanut, Arabidopsis, grape, and soybean, but no collinear CBLL gene pairs between peanut and rice. The prediction results of cis-acting elements showed that AhCBLLs, AdCBLLs, and AiCBLLs contained different proportions of plant growth, abiotic stress, plant hormones, and light response elements. Spatial expression profiles revealed that almost all AhCBLLs had significantly higher expression in pods and seeds. All AhCBLLs could respond to heat stress, and some of them could be rapidly induced by cold, salt, submergence, heat and drought stress. Furthermore, one polymorphic site in AiCBLL7 was identified by association analysis which was closely associated with pod length (PL), pod width (PW), hundred pod weight (HPW) and hundred seed weight (HSW). The results of this study provide a foundation for further research on the function of the CBLL gene family in peanut.

胱硫醚γ合酶（Cystathionine γ-synthase, CGS）、甲硫氨酸γ裂解酶（methionine γ-lyase, MGL）、胱硫醚β裂解酶（cystathionine β-lyase, CBL）以及胱硫醚γ裂解酶（cystathionine γ-lyase, CGL）均含有Cys_Met_Meta_PP结构域，在植物胁迫响应与生长发育进程中发挥关键调控作用。本研究将携带Cys_Met_Meta_PP结构域（PF01053.20）的基因定义为类胱硫醚β裂解酶基因（CBL-like genes, CBLL）。本研究在花生基因组中共鉴定到29个CBLL家族基因，其中12个来自栽培花生，17个来自野生花生种质。上述基因在不同染色体的末端区域呈不均匀分布。进化分析、基因结构分析与保守基序分析结果表明，CBLL蛋白可划分为5个不同的进化分支。染色体分布模式与共线性分析结果有力证实，全基因组复制（异源多倍化，whole-genome duplication, allopolyploidization）是驱动CBLL基因家族扩张的核心因素。比较基因组分析显示，花生、拟南芥、葡萄与大豆之间共存在3组共线性CBLL基因对，而花生与水稻之间未检测到共线性CBLL基因对。顺式作用元件预测结果显示，AhCBLLs、AdCBLLs与AiCBLLs分别携带不同比例的植物生长调控、非生物胁迫响应、植物激素响应及光响应顺式作用元件。组织表达谱分析结果显示，几乎所有AhCBLLs在荚果与种子中均呈现显著高表达。所有AhCBLLs均可响应热胁迫，其中部分基因可被冷、盐、淹水、热击与干旱胁迫快速诱导表达。此外，本研究通过关联分析在AiCBLL7中鉴定到一个多态性位点，该位点与荚果长度（PL）、荚果宽度（PW）、百荚重（HPW）及百粒重（HSW）显著相关。本研究结果为后续解析花生CBLL基因家族的生物学功能奠定了重要基础。