Mitogen-Activated Protein Kinase Kinase Kinases (MAPKKKs/MAP3Ks) are widespread signal transduction module of MAPK cascades and show significant role in growth, development and defense/tolerance responses to environmental stresses. However, MAPKKKs are not yet identified and characterized in the sequenced Cicer arietinum genome and their control on plant defense response against herbivory is still poorly understood. Therefore, a comprehensive investigation of chickpea genome was performed, which identified 52 MAPKKKs (CaMAPKKKs). The phylogenetic study of MAPKKKs from chickpea, Arabidopsis and rice, categorized them into three subclasses, namely MEKK, RAF and ZIK. Presence of respective conserved sequences in each CaMAPKKKs strongly supported their identity as members of the three subfamilies. Physical mapping of these genes revealed their wider distribution on all the eight chromosomes. The three-dimensional structure prediction and potential active sites identification of selected MAPKKK proteins revealed the presence of phosphotransferase domain, which is required for its catalytic activity and participation in the MAPK cascade. The relative expression level of 29 CaMAPKKKs transcripts exhibited differential expression in diverse tissue types, but others showed no/very low expression. Further, in order to figure out their involvement in plant defense response, the expression patterns of CaMAPKKK genes was evaluated during Helicoverpa armigera –feeding by qPCR, which revealed their differential expression during herbivory. This study on identification and characterization of CaMAP3K gene family provided insights into evolution and divergence of CaMAPKKKs and their significance in plant defense against herbivores, which can be further utilized to decipher MAPK pathway involved in plant defense in chickpea and also for pest management.

丝裂原活化蛋白激酶激酶 (MAPKKKs/MAP3Ks) 是 MAPK 级联的广泛信号转导模块，在生长、发育和对环境压力的防御/耐受反应中显示出重要作用。然而，尚未在测序的Cicer arietinum基因组中鉴定和表征MAPKKKs，并且它们对植物对食草动物防御反应的控制仍然知之甚少。因此，对鹰嘴豆基因组进行了全面调查，确定了 52 个 MAPKKKs (CaMAPKKKs)。鹰嘴豆、拟南芥MAPKKKs的系统发育研究和水稻，将它们分为三个子类，即 MEKK、RAF 和 ZIK。每个 CaMAPKKKs 中各自保守序列的存在强烈支持它们作为三个亚家族成员的身份。这些基因的物理图谱揭示了它们在所有八条染色体上的更广泛分布。所选 MAPKKK 蛋白的三维结构预测和潜在活性位点鉴定揭示了磷酸转移酶结构域的存在，这是其催化活性和参与 MAPK 级联所必需的。29 个 CaMAPKKKs 转录本的相对表达水平在不同的组织类型中表现出差异表达，但其他的则没有/非常低的表达。此外，为了弄清楚它们参与植物防御反应，评估了 CaMAPKKK 基因的表达模式。Helicoverpa armigera –通过 qPCR 喂养，揭示了它们在食草期间的差异表达。这项关于 CaMAP3K 基因家族的鉴定和表征的研究提供了对 CaMAPKKKs 的进化和分化及其在植物防御食草动物中的意义的见解，可进一步用于破译参与鹰嘴豆植物防御和害虫管理的 MAPK 通路。