Enhanced expression of vacuolar H+-ATPase subunit E in the roots is associated with the adaptation of Broussonetia papyrifera to salt stress

• Published in: PloS one Vol. 7; no. 10; p. e48183
• Main Authors: Zhang, Min, Fang, Yanming, Liang, Zhenhai, Huang, Libin
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25-10-2012; Public Library of Science (PLoS)
• Subjects: Abiotic stress; Adaptation; Adenosine triphosphatase; Biology; Broussonetia - metabolism; Broussonetia papyrifera; Cytoplasm - metabolism; DNA Primers - genetics; E protein; Forestry; Gene expression; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Glycerol; H+-transporting ATPase; Homeostasis; Hydrogen; Hydrogen-Ion Concentration; Hydrolysis; Immunocytochemistry; Inorganic pyrophosphatase; Intracellular Membranes - metabolism; Ions; Leaves; Models, Statistical; Nucleotides - genetics; Phenotype; Plant cells; Plant Leaves - metabolism; Plant Roots - metabolism; Proteins; Protons; Pyrophosphatase; Roots; Salinity; Salinity effects; Salt; Salts; Salts - chemistry; Sodium chloride; Stress; Stresses; Sucrose; Tissue Distribution; Transcription; Vacuolar Proton-Translocating ATPases - chemistry; Vacuolar Proton-Translocating ATPases - metabolism; Vacuoles - metabolism; Vigna radiata
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0048183

Vacuolar H(+)-ATPase (V-H(+)-ATPase) may play a pivotal role in maintenance of ion homeostasis inside plant cells. In the present study, the expression of V-H(+)-ATPase genes was analyzed in the roots and leaves of a woody plant, Broussonetia papyrifera, which was stressed with 50, 100 and 150 mM NaCl. Moreover, the expression and distribution of the subunit E protein were investigated by Western blot and immunocytochemistry. These showed that treatment of B. papyrifera with NaCl distinctly changed the hydrolytic activity of V-H(+)-ATPase in the roots and leaves. Salinity induced a dramatic increase in V-H(+)-ATPase hydrolytic activity in the roots. However, only slight changes in V-H(+)-ATPase hydrolytic activity were observed in the leaves. In contrast, increased H(+) pumping activity of V-H(+)-ATPase was observed in both the roots and leaves. In addition, NaCl treatment led to an increase in H(+)-pyrophosphatase (V-H(+)-PPase) activity in the roots. Moreover, NaCl treatment triggered the enhancement of mRNA levels for subunits A, E and c of V-H(+)-ATPase in the roots, whereas only subunit c mRNA was observed to increase in the leaves. By Western blot and immunocytological analysis, subunit E was shown to be augmented in response to salinity stress in the roots. These findings provide evidence that under salt stress, increased V-H(+)-ATPase activity in the roots was positively correlated with higher transcript and protein levels of V-H(+)-ATPase subunit E. Altogether, our results suggest an essential role for V-H(+)-ATPase subunit E in the response of plants to salinity stress.