Pepper Novel Serine-Threonine Kinase CaDIK1 Regulates Drought Tolerance via Modulating ABA Sensitivity

Abstract

Adaptation to drought stress is essential for plant growth and development. Plants often adapt to water deficit conditions by activating the ABA signaling. Here, we report that the pepper CaDIK1 (Capsicum annuum Drought Induced Kinase 1) gene is essential for plant tolerance to drought stress. CaDIK1 contains a serine-threonine kinase domain, which plays a role for attachment of phosphate to the target protein. The expression levels of CaDIK1 are upregulated in pepper leaves by ABA, drought, NaCl and H 2 O 2 treatments suggesting its role in abiotic stress response. We used CaDIK1-silenced pepper and CaDIK1-overexpressing (OX) transgenic Arabidopsis plants to evaluate their responses to ABA and drought. CaDIK1-silenced pepper plants conferred a reduced ABA sensitivity and drought hypersensitivity, which was accompanied by high levels of transpirational water loss. CaDIK1-OX plants displayed opposite phenotypes to CaDIK1-silenced peppers. In contrast, substitution of Lys350 to Asn in the kinase domain of CaDIK1 did not lead to alteration of drought sensitivity. Collectively, these data indicate that CaDIK1 is a positive regulator of the ABA-mediated drought-stress tolerance.

Understanding the Impact of Drought in Coffea Genotypes: Transcriptomic Analysis Supports a Common High Resilience to Moderate Water Deficit but a Genotype Dependent Sensitivity to Severe Water Deficit

“…Thus, the highest up-regulation of RLK1 in both CL153 and Icatu under SWD agrees with its role in drought regulation in coffee, most likely also triggered by ABA signaling pathways induced by protein phosphatases as referred above. Ultimately, the primary response beyond ABA levels will be the stomatal closure in coffee leaves, regulating ion transport in guard cells and decreasing drought severity in coffee genotypes as reported in other species [96][97][98] Climate changes are expected to include an increased frequency of water scarcity events, including the intensity of severity and duration, posing a growing threat to coffee's global supply chain. Agroforestry systems can be useful to mitigate some of these harsh effects, reducing the risk of coffee production losses and contributing to the sustainability of crops [18,31].…”

Study of Triticum aestivum Resistome in Response to Wheat dwarf India Virus Infection

“…CaDIK1-silenced pepper plants were found to have reduced ABA sensitivity and drought hypersensitivity [37]. We found higher upregulation of a probe set (Ta.728.1.A1_at) representing serine-threonine kinase in Sonalika in response to virus infection, indicating a possible role in biotic stress as well.…”

Homozygosity mapping identified loci and candidate genes responsible for freezing tolerance in Camelina sativa

“…2022), in pepper (Tang et al., 2022), in arabidopsis (Mao et al., 2010), and in grapevine (Sawicki et al., 2019) during cold exposure/treatment. Intriguingly, modulating serine/threonine kinase ‐based genes have shown to enhance freezing tolerance in arabidopsis (Ding et al., 2015; Mao et al., 2010) and in pepper (Lim et al., 2020). These strengthen our finding and hypothesis that this serine/threonine kinase ‐based gene is probably involved in freezing tolerance and ABA signaling in camelina.…”