ABSTRACT
Ubiquitination is an important protein post-translational modification, which is involved in various cellular processes in higher plants, and U-box E3 ligases play important roles in diverse functions in eukaryotes. Here, we describe the functions of Arabidopsis thaliana PUB19 (AtPUB19), which we demonstrated in an in vitro assay to encode a U-box type E3 ubiquitin ligase. AtPUB19 was up-regulated by drought, salt, cold, and abscisic acid (ABA). Down-regulation of AtPUB19 led to hypersensitivity to ABA, enhanced ABA-induced stomatal closing, and enhanced drought tolerance, while AtPUB19 overexpression resulted in the reverse phenotypes. Molecular analysis showed that the expression levels of a number of ABA and stress marker genes were altered in both AtPUB19 overexpressing and atpub19-1 mutant plants. In summary, our data show that AtPUB19 negatively regulates ABA and drought responses in A. thaliana.
Subject(s)
Abscisic Acid/pharmacology , Arabidopsis/enzymology , Arabidopsis/genetics , Droughts , Stress, Physiological/genetics , Ubiquitin-Protein Ligases/metabolism , Arabidopsis/drug effects , Arabidopsis/physiology , Gene Expression Regulation, Plant/drug effects , Gene Expression Regulation, Plant/genetics , Mutation , Ubiquitin-Protein Ligases/geneticsABSTRACT
Arabidopsis E3 ligase salt- and drought-induced RING-finger 1 (SDIR1) has been found to be involved in abscisic acid (ABA)-related stress signaling. SDIR1-overexpressing Arabidopsis plants exhibit improved tolerance to drought. Tobacco (Nicotiana tabacum) and rice (Oryza sativa) are two important agronomic crop plants. To determine whether SDIR1 enhances drought resistance in crop plants, SDIR1 transgenic tobacco and rice plants were generated. Ectopic expression of SDIR1 in both plants conferred improved drought tolerance ability. These results suggest that SDIR1 can function as a drought-tolerance gene in both dicotyledons and monocotyledons, and that it can serve as a drought-tolerance engineering candidate gene in crop plants.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Disasters , Nicotiana/growth & development , Nicotiana/metabolism , Oryza/growth & development , Oryza/metabolism , Ubiquitin-Protein Ligases/metabolism , Agriculture , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Crops, Agricultural/genetics , Crops, Agricultural/physiology , Oryza/genetics , Plants, Genetically Modified , Nicotiana/genetics , Ubiquitin-Protein Ligases/geneticsABSTRACT
Wheat leaf and seeds at different development stages had been squashed in liquid nitrogen, then lysed by urea buffer which contains 0.1% SDS and 0.1% LDS, denatured protein had been removed by NaAc and chloroform precipitation, total RNA was further purified by LiCl. The RNA we obtained had sharp bands of 28S and 18S after agarose gel electrophoresis, 23S and 16S RNA bands can also be seen clearly in leaf RNA extract, the value of OD260/OD280 of RNA was 2.05-2.105 mg RNA can been isolated from 10 g leaf of wheat. This method can also been used in high molecular weight DNA isolation but the concentration of SDS and LDS must be increased to 1%.
