title: Overexpression of a Plasma Membrane Bound Na+/H+Antiporter-Like Protein (SbNHXLP) Confers Salt Tolerance and Improves Fruit Yield in Tomato by Maintaining Ion Homeostasis.
abstract: A Na+/H+antiporter-like protein (NHXLP) was isolated fromSorghum bicolorL. (SbNHXLP) and validated by overexpressing in tomato for salt tolerance. Homozygous T2transgenic lines when evaluated for salt tolerance, accumulated low Na+and displayed enhanced salt tolerance compared to wild-type plants (WT). This is consistent with the amiloride binding assay of the protein. Transgenics exhibited higher accumulation of proline, K+, Ca2+, improved cambial conductivity, higher PSII, and antioxidative enzyme activities than WT. Fluorescence imaging results revealed lower Na+and higher Ca2+levels in transgenic roots. Co-immunoprecipitation experiments demonstrate thatSbNHXLP interacts with aSolanum lycopersicumcation proton antiporter protein2 (SlCHX2). qRT-PCR results showed upregulation ofSbNHXLPandSlCHX2upon treatment with 200 mM NaCl and 100 mM potassium nitrate.SlCHX2is known to be involved in K+acquisition, and the interaction between these two proteins might help to accumulate more K+ions, and thus maintain ion homeostasis. These results strongly suggest that plasma membrane boundSbNHXLP involves in Na+exclusion, maintains ion homeostasis in transgenics in comparison with WT and alleviates NaCl stress.
authors.affiliation: Department of Genetics, Osmania University Hyderabad, India.
authors.forename: P Hima
authors.initials: PH
authors.lastname: Kumari
authors.affiliation: Department of Genetics, Osmania University Hyderabad, India.
authors.forename: S Anil
authors.initials: SA
authors.lastname: Kumar
authors.affiliation: Department of Biosciences, Sardar Patel University Anand, India.
authors.forename: Pramod
authors.initials: P
authors.lastname: Sivan
authors.affiliation: Department of Biological Sciences, College of Science and Technology, Florida A&M University Tallahassee, FL, USA.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Katam
authors.affiliation: Bioclues Organization Hyderabad, India.
authors.forename: Prashanth
authors.initials: P
authors.lastname: Suravajhala
authors.affiliation: Department of Biosciences, Sardar Patel University Anand, India.
authors.forename: K S
authors.initials: KS
authors.lastname: Rao
authors.affiliation: Center of Excellence in Genomics, International Crops Research Institute for the Semi-Arid Tropics Hyderabad, India.
authors.forename: Rajeev K
authors.initials: RK
authors.lastname: Varshney
authors.affiliation: Department of Genetics, Osmania University Hyderabad, India.
authors.forename: Polavarapu B Kavi
authors.initials: PB
authors.lastname: Kishor
keywords: CHX2; SbNHXLP; co-immunoprecipitation; salt stress; tomato