背景:丝裂原活化蛋白激酶(MAPK)级联是至关重要的细胞信号转导机制,在植物生长发育中起着重要作用,新陈代谢,和应激反应。MAPK级联包括三种蛋白激酶,MAPK,MAPKK,还有MAPKKK.这三种蛋白激酶通过顺序磷酸化介导下游反应分子的信号传导。MAPK基因家族已在许多植物中被鉴定和分析,然而,它尚未在苜蓿中进行调查。
结果:在这项研究中,在四倍体苜蓿基因组中鉴定了紫花苜蓿MAPK基因(称为MsMAPKs)。80个MsMAPK分为四组,A组有8个,B组21人,C组中为21,D组中为30。MsMAPK的基本结构分析显示存在保守的TXY基序。A组,B和C包含一个TEY图案,而D组包含一个TDY基序。RNA-seq分析揭示了两种MsMAPK的组织特异性和35种MsMAPK的全组织表达。进一步分析确定了MsMAPK成员对干旱的反应,盐,和寒冷的压力条件。两个MsMAPKs(MsMAPK70和MsMAPK75)响应盐和冷胁迫;两个MsMAPKs(MsMAPK60和MsMAPK73)响应冷胁迫和干旱胁迫;四个MsMAPKs(MsMAPK1,MsMAPK33,MsMAPK64和MsMAPK71)响应盐和干旱胁迫;两个M
结论:本研究全面鉴定并分析了苜蓿MAPK基因家族。通过分析RNA-seq数据筛选与非生物胁迫相关的候选基因。研究结果为进一步分析苜蓿MAPK基因的功能和提高抗逆性提供了关键信息。
BACKGROUND: The mitogen-activated protein kinase (MAPK) cascade is crucial cell signal transduction mechanism that plays an important role in plant growth and development, metabolism, and stress responses. The MAPK cascade includes three protein kinases, MAPK, MAPKK, and MAPKKK. The three protein kinases mediate signaling to downstream response molecules by sequential phosphorylation. The MAPK gene family has been identified and analyzed in many plants, however it has not been investigated in alfalfa.
RESULTS: In this study, Medicago sativa MAPK genes (referred to as MsMAPKs) were identified in the tetraploid alfalfa genome. Eighty MsMAPKs were divided into four groups, with eight in group A, 21 in group B, 21 in group C and 30 in group D. Analysis of the basic structures of the MsMAPKs revealed presence of a conserved TXY motif. Groups A, B and C contained a TEY motif, while group D contained a TDY motif. RNA-seq analysis revealed tissue-specificity of two MsMAPKs and tissue-wide expression of 35 MsMAPKs. Further analysis identified MsMAPK members responsive to drought, salt, and cold stress conditions. Two MsMAPKs (MsMAPK70 and MsMAPK75) responds to salt and cold stresses; two MsMAPKs (MsMAPK60 and MsMAPK73) responds to cold and drought stresses; four MsMAPKs (MsMAPK1, MsMAPK33, MsMAPK64 and MsMAPK71) responds to salt and drought stresses; and two MsMAPKs (MsMAPK5 and MsMAPK7) responded to all three stresses.
CONCLUSIONS: This study comprehensively identified and analysed the alfalfa MAPK gene family. Candidate genes related to abiotic stresses were screened by analysing the RNA-seq data. The results provide key information for further analysis of alfalfa MAPK gene functions and improvement of stress tolerance.