Genome-wide identification and functional characterization of cotton (Gossypium hirsutum) MAPKKK gene family in response to drought stress

Abstract

Background: Mitogen-activated protein kinase kinase kinases (MAPKKKs) are significant components in the MAPK signal pathway and play essential roles in regulating plants against drought stress. To explore MAPKKK gene family functioning in cotton response and resistance to drought stress, we conducted a systematic analysis of GhMAPKKKs. Results: In this study, 157 nonredundant GhMAPKKKs (including 87 RAFs, 46 MEKKs and 24 ZIKs) were identified in cotton (Gossypium hirsutum). These GhMAPKKK genes are unevenly distributed on 26 chromosomes, and segmental duplication is the major way for the enlargement of MAPKKK family. Furthermore, members within the same subfamily share a similar gene structure and motif composition. A lot of cis-elements relevant to plant growth and response to stresses are distributed in promoter regions of GhMAPKKKs. Additionally, these GhMAPKKKs show differential expression patterns in cotton tissues. The transcription levels of most genes were markedly altered in cotton under heat, cold and PEG treatments, while the expressions of some GhMAPKKKs were induced in cotton under drought stress. Among these drought-induced genes, we selected GhRAF4 and GhMEKK12 for further functional characterization by virus-induced gene silencing (VIGS) method. The experimental results indicated that the gene-silenced cotton displayed decreased tolerance to drought stress. Malondialdehyde (MDA) content was higher, but proline accumulation, relative leaf water content and activities of superoxide dismutase (SOD) and peroxidase (POD) were lower in the gene-silenced cotton, compared with those in the controls, under drought stress. Conclusion: Collectively, a systematic survey of gene structure, chromosomal location, motif composition and evolutionary relationship of MAPKKKs were performed in upland cotton (Gossypium hirsutum). The following expression and functional study showed that some of them take important parts in cotton drought tolerance. Thus, the data presented here may provide a foundation for further investigating the roles of GhMAPKKKs in cotton response and resistance to drought stress.

Genome-wide characterization and expression profiling of MAPK cascade genes in Salvia miltiorrhiza reveals the function of SmMAPK3 and SmMAPK1 in secondary metabolism

“…A number of studies have focused on systematically identifying and characterizing the proteins participating in plant MAPK cascades [48][49][50][51], which affect various aspects of both growth and development [18,52,53], stress tolerance [23,24,34,54] and the synthesis of secondary metabolites [17,26,33]. The present research has extended the scope of these studies to the medicinal species S. miltiorrhiza, made possible by the recent acquisition of its genomic sequence [46].…”

Genome‐wide analysis of mitogen‐activated protein (MAP) kinase gene family expression in response to biotic and abiotic stresses in sugarcane

“…Recently, numerous genome‐wide analyses of MAPK , MAPKK and MAPKKK gene families have been performed in diverse plant species, providing insights into the mechanisms underlying the regulation of MAP kinase modules and laying an important foundation for further functional characterization (He et al 2020). The number of MAPK , MAPKK and MAPKKK gene family members varies among different plant species: 3 MAPK genes in the lower eukaryotic plant Ostreocccus lucimarinus (Mohanta et al 2015) compared to 38 in Glycine max (Neupane et al 2013); 5 MAPKK genes in Solanum lycopersicum (Wu et al 2014), Ziziphus jujube (Liu et al 2017), and Jatropha curcas (Wang et al 2018) compared to 18 in Triticum aestivum (Zhan et al 2017); and 33 MAPKKK genes in Pyropia yezoensis (Kong et al 2020) compared to 157 in Gossypium hirsutum (Zhang et al 2020). In this study, 15 ShMAPK , 6 ShMAPKK and 16 ShMAPKKK genes were identified in the Saccharum spp.…”

Mitogen-Activated Protein Kinase CaDIMK1 Functions as a Positive Regulator of Drought Stress Response and Abscisic Acid Signaling in Capsicum annuum

“…KAF3666587.1 ) shares relatively high identities/similarities (46.74–81.85%/63.73–86.61%) with the MAP3K proteins, in particular belonging to MEKK subfamily, from several higher plant species. A phylogenetic tree analysis was conducted using MAPKKK-MEKK proteins of the model plant Arabidopsis , together with drought- and/or ABA-responsive MEKK kinases from rice, cotton, tobacco, and tomato, characterized in previous studies ( Ichimura et al, 2002 ; Shou et al, 2004 ; Rao et al, 2010 ; Wu et al, 2014 ; Mao et al, 2019 ; Na et al, 2019 ; Zhang et al, 2020 ). As shown in Figure 2 , CaDIMK1, CA07g11520, CA07g11530, CA07g11540, CA07g11550, and CA07g11570 were clustered with AtMAPKKK15/16/17/18, SlMAPKKK51/53/55, OsMAPKKK62/63, and GhMEKK12.…”

“…Previous studies have revealed an ABA-induced regulation of those Arabidopsis MAPKKK gene expression ( Wang et al, 2011 ; Danquah et al, 2015 ) and functional involvement of some genes in ABA signaling ( Mitula et al, 2015 ; Li Y. et al, 2017 ). Also, AtMAPKKK18 and GhMEKK12 play a positive role in drought tolerance of Arabidopsis and cotton, respectively ( Li K. et al, 2017 ; Zhang et al, 2020 ). Based on these results, we proposed that CaDIMK1 could be involved in plant responses to ABA and drought stress.…”