Arabidopsis AHP2, AHP3, and AHP5 histidine phosphotransfer proteins function as redundant negative regulators of drought stress response

Abstract

Cytokinin is an essential phytohormone controlling various biological processes, including environmental stress responses. In Arabidopsis, although the cytokinin (CK)-related phosphorelay-consisting of three histidine kinases, five histidine phosphotransfer proteins (AHPs), and a number of response regulators-has been known to be important for stress responses, the AHPs required for CK signaling during drought stress remain elusive. Here, we report that three Arabidopsis AHPs, namely AHP2, AHP3, and AHP5, control responses to drought stress in negative and redundant manner. Loss of function of these three AHP genes resulted in a strong drought-tolerant phenotype that was associated with the stimulation of protective mechanisms. Specifically, cell membrane integrity was improved as well as an increased sensitivity to abscisic acid (ABA) was observed rather than an alteration in ABA-mediated stomatal closure and density. Consistent with their negative regulatory functions, all three AHP genes' expression was down-regulated by dehydration, which most likely resulted from a stress-induced reduction of endogenous CK levels. Furthermore, global transcriptional analysis of ahp2,3,5 leaves revealed down-regulation of many well-known stress-and/or ABA-responsive genes, suggesting that these three AHPs may control drought response in both ABA-dependent and ABA-independent manners. The discovery of mechanisms of activation and the targets of the downstream components of CK signaling involved in stress responses is an important and challenging goal for the study of plant stress regulatory network responses and plant growth. The knowledge gained from this study also has broad potential for biotechnological applications to increase abiotic stress tolerance in plants.microarray analysis | plant adaptation | stress mitigation | two-component system

Positive regulatory role of strigolactone in plant responses to drought and salt stress

“…Rosette leaves of three independent WT and SL-signaling max2-3 mutant plants treated for 0, 2, 4, and 6 h were then collected to make three biological replicates for microarray and expression analyses. Microarray analysis by using the Arabidopsis Oligo 44K DNA microarray (version 4.0; Agilent Technology) was performed as described previously (35,36). The microarray data and a detailed protocol were deposited in the Gene Expression Omnibus database (accession no.…”

The SrkA Kinase Is Part of the SakA Mitogen-Activated Protein Kinase Interactome and Regulates Stress Responses and Development in Aspergillus nidulans

“…The use of phosphorelay systems to perceive oxidative stress and other types of environmental stress is conserved in bacteria, plants (12), and fungi (13). The fission yeast Schizosaccharomyces pombe uses a multistep phosphorelay composed of the Mak2/3 sensor histidine kinases, Mpr1 HPt protein, and Mcs4 response regulator to transmit H 2 O 2 stress signals to the Spc1 (also known as StyI) mitogen-activated protein kinase (MAPK) cascade (14,15).…”

On the roles of genes encoding methionine-rich proteins in Arabidopsis thaliana in response to abiotic stresses

“…Số liệu từ các nghiên cứu trước đây của chúng tôi [23,24] được tải xuống và phân tích bằng MS EXCEL.…”

“…Đây được coi là những yếu tố gây nguy hại nhất cho thực vật, ảnh hưởng nghiêm trọng đến sinh trưởng, phát triển và năng suất của cây trồng [26,32]. Dựa trên kết quả phân tích biểu hiện gen bằng microarray công bố trước đây trên cây Arabidopsis thaliana xử lý hạn và mặn, chúng tôi đã khai thác được mức độ phiên mã của gen AtMRP [23,24]. Nishiyama et al (2013) [24] đã nghiên cứu dữ liệu biểu hiện của dòng đột biến AHPs và kiểu dại (Col-0) trong điều kiện hạn và đủ nước (đối chứng).…”

“…Dựa trên kết quả phân tích biểu hiện gen bằng microarray công bố trước đây trên cây Arabidopsis thaliana xử lý hạn và mặn, chúng tôi đã khai thác được mức độ phiên mã của gen AtMRP [23,24]. Nishiyama et al (2013) [24] đã nghiên cứu dữ liệu biểu hiện của dòng đột biến AHPs và kiểu dại (Col-0) trong điều kiện hạn và đủ nước (đối chứng). Kết quả phân tích được thu thập từ GEO có mã truy cập là GSE42290.…”