Abstract
Salt stress is one of the major environmental stresses in agriculture worldwide and affects crop productivity and quality. The development of crops with elevated levels of salt tolerance is therefore highly desirable. In the present study, a novel maspardin gene, named IbMas, was isolated from salt-tolerant sweetpotato (Ipomoea batatas (L.) Lam.) line ND98. IbMas contains maspardin domain and belongs to α/β-hydrolase superfamily. Expression of IbMas was up-regulated in sweetpotato under salt stress and ABA treatment. The IbMas-overexpressing sweetpotato (cv. Shangshu 19) plants exhibited significantly higher salt tolerance compared with the wild-type. Proline content was significantly increased, whereas malonaldehyde content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD) and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbMas up-regulated the salt stress responsive genes, including pyrroline-5-carboxylate synthase, pyrroline-5-carboxylate reductase, SOD, psbA and phosphoribulokinase genes, under salt stress. These findings suggest that overexpression of IbMas enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and increasing reactive oxygen species scavenging capacity.
Highlights
Soil salinization is becoming a serious threat to world agriculture to support a rapidly growing population [1, 2]
The maspardin gene has not been characterized at the functional level in plants
A BLASTX search indicated that no homolog of known function was similar to IbMas in plants, while the amino acid sequence of IbMas showed 66.99% to 71.53% amino acid identity with predicted protein products of XP_002509605 from Ricinus communis, KDP25601 from Jatropha curcas, XP_006368699 from Populus trichocarpa, EXC17874 from Morus notabilis, XP_004245715 from Solanum lycopersicum, XP_002267811 from Vitis vinifera, XP_007039974 from Theobroma cacao and XP_006363736 from Solanum tuberosum
Summary
Soil salinization is becoming a serious threat to world agriculture to support a rapidly growing population [1, 2]. 20% of the irrigated soils in the world are under salt stress, and soil salinization has become a major constraint limiting crop production [3, 4]. The development of crops with elevated levels of salt tolerance is highly desirable. The ESTHER database, which is freely available via a web server (http://bioweb.ensam.inra.fr/esther) and is widely used, is dedicated to proteins with the a/b-hydrolase fold, and it currently contains. 000 manually curated proteins [9]. The biological functions of a/b-hydrolase fold enzymes in various organisms are widely ranging and include biosynthesis, metabolism, signal transduction and gene regulation [8]. A few of a/b-hydrolase fold enzymes such as esterase, phospholipase D and OsPOP5 have been shown to be involved in plant salt tolerance [10,11,12,13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
