Overlapping functions of YDA and MAPKKK3/MAPKKK5 upstream of MPK3/MPK6 in plant immunity and growth/development

Abstract

Arabidopsis MITOGEN‐ACTIVATED PROTEIN KINASE3 (MAPK3 or MPK3) and MPK6 play important signaling roles in plant immunity and growth/development. MAPK KINASE4 (MKK4) and MKK5 function redundantly upstream of MPK3 and MPK6 in these processes. YODA (YDA), also known as MAPK KINASE KINASE4 (MAPKKK4), is upstream of MKK4/MKK5 and forms a complete MAPK cascade (YDA–MKK4/MKK5–MPK3/MPK6) in regulating plant growth and development. In plant immunity, MAPKKK3 and MAPKKK5 function redundantly upstream of the same MKK4/MKK5–MPK3/MPK6 module. However, the residual activation of MPK3/MPK6 in the mapkkk3 mapkkk5 double mutant in response to flg22 pathogen‐associated molecular pattern (PAMP) treatment suggests the presence of additional MAPKKK(s) in this MAPK cascade in signaling plant immunity. To investigate whether YDA is also involved in plant immunity, we attempted to generate mapkkk3 mapkkk5 yda triple mutants. However, it was not possible to recover one of the double mutant combinations (mapkkk5 yda) or the triple mutant (mapkkk3 mapkkk5 yda) due to a failure of embryogenesis. Using the clustered regularly interspaced short palindromic repeats (CRISPR) – CRISPR‐associated protein 9 (Cas9) approach, we generated weak, N‐terminal deletion alleles of YDA, yda‐del, in a mapkkk3 mapkkk5 background. PAMP‐triggered MPK3/MPK6 activation was further reduced in the mapkkk3 mapkkk5 yda‐del mutant, and the triple mutant was more susceptible to pathogen infection, suggesting YDA also plays an important role in plant immune signaling. In addition, MAPKKK5 and, to a lesser extent, MAPKKK3 were found to contribute to gamete function and embryogenesis, together with YDA. While the double homozygous mapkkk3 yda mutant showed the same growth and development defects as the yda single mutant, mapkkk5 yda double mutant and mapkkk3 mapkkk5 yda triple mutants were embryo lethal, similar to the mpk3 mpk6 double mutants. These results demonstrate that YDA, MAPKKK3, and MAPKKK5 have overlapping functions upstream of the MKK4/MKK5–MPK3/MPK6 module in both plant immunity and growth/development.

StMAPKK5 Positively Regulates Response to Drought and Salt Stress in Potato

“…Among them, MAPKKs have the fewest number of members, and to date, 83 MAPKKKs, 5 MAPKKs, and 15 MAPKKs have been identified from the whole potato genome [9]. The MAPK cascade is a crucial signaling module downstream of receptors and sensors that not only senses endogenous and exogenous stimuli [10,11], but also amplifies and transmits the exogenous signals step by step through phosphorylation sequential activation to participate in plant growth and development, stress tolerance, and generate specific physiological and biochemical responses in response to adverse environmental changes [12,13]. A large number of studies have shown that MAPKK plays an important role in plant growth, development, and response to abiotic stresses.…”

A signaling cascade mediating fruit trait development via phosphorylation‐modulated nuclear accumulation of JAZ repressor

“…Mitogen-activated protein kinases play vital roles in plant growth, development and adaptions to biotic/abiotic stresses (Colcombet and Hirt, 2008;Meng and Zhang, 2013;Sun and Zhang, 2022). Among the MAPKs, AtMPK6 in A. thaliana or its homologs in other plant species, have been increasingly attracting a special interest from plant scientists owing to its vital roles in the regulation of diverse biological processes (Daneshkhah et al, 2018;Lee et al, 2019;Fernandez et al, 2020;Yan et al, 2021;Zou et al, 2021;Lang et al, 2022;Liu et al, 2022;Wu et al, 2022;Zhou et al, 2022;Li et al, 2022;Ai et al, 2023;Jeon et al, 2023;Xing et al, 2023;Yu et al, 2023;Wang et al, 2023a). In one of our previous studies, we found that FvMPK6 acts to modulate strawberry fruit trait development; moreover, it was found that the activity of FvMPK6 was able to respond to multiple environmental stimuli, such as salt, dehydration, cold and high temperature stresses (Wang et al, 2021).…”

Identification and validation of quantitative trait loci for fertile spikelet number per spike and grain number per fertile spikelet in bread wheat (Triticum aestivum L.)

“…Furthermore, OsMKKK10, OsMKK4, and OsMAPK6 form an OsMKKK10-OsMKK4-OsMAPK6 signaling pathway, participate in the formation of rice ear morphology (Guo et al 2018;Xu et al 2018;Guo et al 2020b). The mutation of MAPKKK4 in Arabidopsis thaliana participates in the biological process of inflorescence development, and stomatal complex morphogenesis (Li et al 2019a;Wang et al 2022;Guo et al 2022;Liu et al 2022). Multiple SNPs/InDels were detected in the upstream region of TraesCS2A03G0978700 (Table S9), which may change the expression level and affect the function of the gene (Li et al 2019b).…”