Two cysteine proteinase inhibitors from Arabidopsis thaliana, AtCYSa and AtCYSb, increasing the salt, drought, oxidation and cold tolerance

Abstract

Two cysteine proteinase inhibitors (cystatins) from Arabidopsis thaliana, designated AtCYSa and AtCYSb, were characterized. Recombinant GST-AtCYSa and GST-AtCYSb were expressed in Escherichia coli and purified. They inhibit the catalytic activity of papain, which is generally taken as evidence for cysteine proteinase inhibitor function. Northern blot analyses showed that the expressions of AtCYSa and AtCYSb gene in Arabidopsis cells and seedlings were strongly induced by multiple abiotic stresses from high salt, drought, oxidant, and cold. Interestingly, the promoter region of AtCYSa gene contains a dehydration-responsive element (DRE) and an abscisic acid (ABA)-responsive element (ABRE), which identifies it as a DREB1A and AREB target gene. Under normal conditions, AtCYSa was expressed in 35S: DREB1A and 35S: AREB1 plants at a higher level than in WT plants, while AtCYSa gene was expressed in 35S: DREB2A plants at the same level as in WT plants. Under stress conditions (salt, drought and cold), AtCYSa was expressed more in all three transgenic plants than in WT plants. Over-expression of AtCYSa and AtCYSb in transgenic yeast and Arabidopsis plants increased the resistance to high salt, drought, oxidative, and cold stresses. Taken together, these data raise the possibility of using AtCYSa and AtCYSb to genetically improve environmental stresses tolerance in plants.

Identification of BZR1-interacting Proteins as Potential Components of the Brassinosteroid Signaling Pathway in Arabidopsis Through Tandem Affinity Purification

“…Inhibitor-CYSB is a cysteine protease inhibitor (41,42). Its interaction with BZR1 was further confirmed through an in vitro pull-down assay (Fig.…”

“…Whether CYSB acts downstream of BZR1 remains to be tested. It was reported that CYSB overexpression increases plant tolerance to abiotic stress (41,42). Whether the increase in tolerance is related to BZR1 and whether the CYSB-BZR1 interaction is functional under conditions of stress requires further evaluation.…”

iTRAQ Protein Profile Analysis of Arabidopsis Roots Reveals New Aspects Critical for Iron Homeostasis

“…Phytocystatins belong to a superfamily of Cys proteases widely distributed among eukaryotes. Plant cystatins have well-documented roles in developmental processes and biotic and abiotic stresses (Gaddour et al, 2001;Zhang et al, 2008;Hwang et al, 2010). Root expression of CYS2 was confined to the root tip, representing the first root/soil contact point.…”

Coupling mutagenesis and parallel deep sequencing to probe essential residues in a genome or gene

“…Altogether, these data provide evidence that HY5 has an important function in regulating cold-induced gene expression. Several HY5-regulated cold-inducible genes, including those validated by qPCR, are related to cold acclimation (18)(19)(20)(21), suggesting that HY5 may also have a role in this adaptive response.…”