title: Enhanced salt stress tolerance of rice plants expressing a vacuolar H+ -ATPase subunit c1 (SaVHAc1) gene from the halophyte grass Spartina alterniflora Löisel.
abstract: The physiological role of a vacuolar ATPase subunit c1 (SaVHAc1) from a halophyte grass Spartina alterniflora was studied through its expression in rice. The SaVHAc1-expressing plants showed enhanced tolerance to salt stress than the wild-type plants, mainly through adjustments in early stage and preparatory physiological responses. In addition to the increased accumulation of its own transcript, SaVHAc1 expression led to increased accumulation of messages of other native genes in rice, especially those involved in cation transport and ABA signalling. The SaVHAc1-expressing plants maintained higher relative water content under salt stress through early stage closure of the leaf stoma and reduced stomata density. The increased K(+) /Na(+)  ratio and other cations established an ion homoeostasis in SaVHAc1-expressing plants to protect the cytosol from toxic Na(+)  and thereby maintained higher chlorophyll retention than the WT plants under salt stress. Besides, the role of SaVHAc1 in cell wall expansion and maintenance of net photosynthesis was implicated by comparatively higher root and leaf growth and yield of rice expressing SaVHAc1 over WT under salt stress. The study indicated that the genes contributing toward natural variation in grass halophytes could be effectively manipulated for improving salt tolerance of field crops within related taxa.
authors.affiliation: School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA. nbaisakh@agcenter.lsu.edu
authors.forename: Niranjan
authors.initials: N
authors.lastname: Baisakh
authors.forename: Mangu V
authors.initials: MV
authors.lastname: RamanaRao
authors.forename: Kanniah
authors.initials: K
authors.lastname: Rajasekaran
authors.forename: Prasanta
authors.initials: P
authors.lastname: Subudhi
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Janda
authors.forename: David
authors.initials: D
authors.lastname: Galbraith
authors.forename: Cheryl
authors.initials: C
authors.lastname: Vanier
authors.forename: Andy
authors.initials: A
authors.lastname: Pereira
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D040582:Inheritance Patterns / Q000187:drug effects / Q000235:genetics; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects; D018520:Plant Shoots / Q000033:anatomy & histology / Q000187:drug effects; D054046:Plant Stomata / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D006109:Poaceae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D011188:Potassium / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055049:Salt Tolerance / Q000187:drug effects / Q000235:genetics*; D055051:Salt-Tolerant Plants / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D017422:Sequence Analysis, DNA; D013054:Spectrophotometry, Atomic; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics* / Q000378:metabolism; D014867:Water
chemical_list: D014867:Water; D002734:Chlorophyll; D025262:Vacuolar Proton-Translocating ATPases; D011188:Potassium