Abstract：
ABA signaling core components PYR/PYL, group A PP2C and SnRK2 play important roles in various environmental stress responses of plants. This study identified 14 PYR/PYL, 9 PP2C (A), and 10 SnRK2 genes from halophytic Eutrema. Phylogenetic analysis showed 4 EsPYR/PYL, 4 EsPP2C (A) and 3 EsSnRK2 subfamilies characterized, which was supported by their gene structures and protein motifs. Large-scale segmental duplication event was demonstrated to be a major contributor to expansion of the EsPYL-PP2C (A)-SnRK2 gene families. Synteny relationship analysis revealed more orthologous PYL-PP2C (A)-SnRK2 gene pairs located in collinear blocks between Eutrema and Brassica than that between Eutrema and Arabidopsis. RNA-seq and qRT-PCR revealed EsABI1, EsABI2 and EsHAL2 showed a significantly up-regulated expression in leaves and roots in response to ABA, NaCl or cold stress. Three markedly co-expression modules of ABA/R-brown, NaCl/L-lightsteelblue1 and Cold/R-lightgreen were uncovered to contain EsPYL-PP2C (A)-SnRK2 genes by WGCNA analysis. GO and KEGG analysis indicated that the genes of ABA/R-brown module containing EsHAB1, EsHAI2 and EsSnRK2.6 were enriched in proteasome pathway. Further, EsHAI2-OE transgenic Arabidopsis lines showed significantly enhanced seeds germination and seedlings growth. This work provides a new insight for elucidating potential molecular functions of PYL-PP2C (A)-SnRK2 responding to ABA and abiotic stresses.
摘要：
ABA信号核心成分PYR/PYL,A组PP2C和SnRK2在植物的各种环境胁迫反应中起重要作用。本研究确定了14个PYR/PYL，9PP2C（A），和10个来自盐生植物Eutrema的SnRK2基因。系统发育分析显示4个EsPYR/PYL,4个EsPP2C（A）和3个EsSnRK2亚家族，它们的基因结构和蛋白质基序支持。大规模的分段复制事件被证明是EsPYL-PP2C（A）-SnRK2基因家族扩展的主要原因。合成关系分析显示，与Eutrema和拟南芥相比，Eutrema和Brassica之间的直系同源PYL-PP2C（A）-SnRK2基因对更多。RNA-seq和qRT-PCR显示EsABI1，EsABI2和EsHAL2在叶片和根中显示出响应ABA的显着上调表达，NaCl或冷胁迫。ABA/R-棕色的三个显著共表达模块，通过WGCNA分析发现NaCl/L-lightsteelblue1和Cold/R-lightgreen含有EsPYL-PP2C（A）-SnRK2基因。GO和KEGG分析表明，含有EsHAB1，EsHAI2和EsSnRK2.6的ABA/R-棕色模块基因在蛋白酶体途径中富集。Further,EsHAI2-OE转基因拟南芥株系显示出显着增强的种子萌发和幼苗生长。这项工作为阐明PYL-PP2C（A）-SnRK2响应ABA和非生物胁迫的潜在分子功能提供了新的见解。
