Arabidopsis YAK1 regulates abscisic acid response and drought resistance

Abstract

Abscisic acid (ABA) is an important phytohormone that controls several plant processes such as seed germination, seedling growth, and abiotic stress response. Here, we report that AtYak1 plays an important role in ABA signaling and postgermination growth in Arabidopsis. AtYak1 knockout mutant plants were hyposensitive to ABA inhibition of seed germination, cotyledon greening, seedling growth, and stomatal movement. atyak1-1 mutant plants display reduced drought stress resistance, as evidenced by water loss rate and survival rate. Molecular genetic analysis revealed that AtYak1 deficiency led to elevated expression of stomatal-related gene, MYB60, and down-regulation of several stress-responsive genes. Altogether, these results indicate that AtYak1 plays a role as a positive regulator in ABA-mediated drought response in Arabidopsis.

Plant dual‐specificity tyrosine phosphorylation‐regulated kinase optimizes light‐regulated growth and development in Arabidopsis

“…Therefore, although AtYAK1 positively regulates ABA responses (Kim et al . ), the involvement of AtYAK1 in early photomorphogenic development does not likely result from ABA action.…”

“…reported that AtYAK1 is a positive regulator of ABA responses, and atyak1–1 has an early germination phenotype (Kim et al . ). However, the germination rates of atyak1–2 or atyak1–3 and Col‐0 were indistinguishable under conditions used in this study (Supporting Information Fig.…”

“…In addition, the elevated ABI5 level could not account for the long hypocotyl phenotype in atyak1. Therefore, although AtYAK1 positively regulates ABA responses (Kim et al 2016), the involvement of AtYAK1 in early photomorphogenic development does not likely result from ABA action.…”

“…Apart from being a positive regulator of abscisic acid (ABA) responses under drought stress (Kim et al . ), the function of AtYAK1 in Arabidopsis remains obscure. Proteomic studies via mass spectrometry have suggested the co‐existence of orthologous proteins of AtYAK1 and a WD‐repeat protein in the same protein complex in yeast (Ho et al .…”

“…The AtYAK1 is a member of the DYRK family in the YAK1 clade (Kajikawa et al 2015;Schulz-Raffelt et al 2016). Apart from being a positive regulator of abscisic acid (ABA) responses under drought stress (Kim et al 2016), the function of AtYAK1 in Arabidopsis remains obscure. Proteomic studies via mass spectrometry have suggested the co-existence of orthologous proteins of AtYAK1 and a WD-repeat protein in the same protein complex in yeast (Ho et al 2002) and mammalian cells (Miyata & Nishida 2011;Skurat & Dietrich 2004).…”