Response Of Arabidopsis Protein Kinase AtPKL1 To ABA And Ca^2＋ Treatment

Plant receptor protein kinases are a subfamily of plant protein kinase. It can transform extracellular signals into intracellular signals through phosphorylation and dephosphorylation and turn on or off downstream target proteins, which mediated a variety of physiological and biochemical reactions induced by extracellular plant hormones and environmental signals. In this study, we explored the functions of protein kinase AtPKL1 in response to ABA and Ca²⁺ treatment used wild-type Arabidopsis, the T-DNA insertion mutant of Atpkl1 and AtPKL1-overexpression homozygote as the material, the results are as follows:1. Genes differentially expressed after ABA treatment between Arabidopsis wild-type and Atpkl1 mutant were examined by GeneFishing, and one gene named CaEF showed significantly difference between the two samples. Database search indicates that this gene encodes a Ca²⁺ binding protein. Northern blotting analysis confirmed that CaEF is indeed induced by ABA treatment in Atpkl1 mutant.2. AtPKL1 over expression recombinant plamid was constructed and was transformed into wild type Arabidopsis thaliana by agrobacterium-mediated infection. The obtained transgenic homozygotes were subjected to ABA and Ca²⁺ treatment. The results showed that over-expression of AtPKL1 lead to a lower germination rate in transgenic lines than in wild-type under both treatments, while the germination rate in Atpkl1 mutant is higher than that in wild-type, and showed a clear dose-dependent response.