title: OsSEC24, a functional SEC24-like protein in rice, improves tolerance to iron deficiency and high pH by enhancing H(+) secretion mediated by PM-H(+)-ATPase.
abstract: Iron is abundant in the soil, but its low solubility in neutral or alkaline soils limits its uptake. Plants can rely on rhizosphere acidification to increase iron solubility. OsSEC27p was previously found to be a highly up-regulated gene in iron-deficient rice roots. Here, pH-dependent complementation assays using yeast mutants sec24Δ/SEC24 and sec27Δ/SEC27 showed that OsSEC27 could functionally complement SEC24 but not SEC27 in yeast; thus, it was renamed as OsSEC24. We found that OsSEC24-transgenic tobacco plants increased the length and number of roots under iron deficiency at pH 8.0. To explore how OsSEC24 confers tolerance to iron deficiency, we utilized transgenic tobacco, rice and rice protoplasts. H(+) flux measurements using Non-invasive Micro-test Technology (NMT) indicated that the transgenic OsSEC24 tobacco and rice enhanced H(+) efflux under iron deficiency. Conversely, the application of plasma membrane PM-H(+)-ATPase inhibitor vanadate elucidated that H(+) secretion increased by OsSEC24 was mediated by PM-H(+)-ATPase. OsPMA2 was used as a representative of iron deficiency-responsive PM-H(+)-ATPases in rice root via RT-PCR analysis. In transgenic rice protoplasts OsPMA2 was packaged into OsSEC24 vesicles after export from the ER through confocal-microscopy observation. Together, OsSEC24 vesicles, along with PM-H(+)-ATPases stimulate roots formation under iron deficiency by enhancing rhizosphere acidification.
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Xiao-Xi
authors.initials: XX
authors.lastname: Pan
authors.affiliation: Department of Biological Sciences, State University of New York, Buffalo, NY 14260, USA.
authors.forename: James O
authors.initials: JO
authors.lastname: Berry
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.lastname: Naren
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Ma
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Song
authors.initials: S
authors.lastname: Tan
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Institute of Mathematics and Interdisciplinary Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Wei-Zhong
authors.initials: WZ
authors.lastname: Zhao
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China.
authors.forename: Xian-Yong
authors.initials: XY
authors.lastname: Sheng
authors.affiliation: College of Life Sciences, Capital Normal University, No. 105 Xisanhuan North Street, Beijing 100048, China. Electronic address: yinlp@cnu.edu.cn.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Yin
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006863:Hydrogen-Ion Concentration; D000090463:Iron Deficiencies; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D006180:Proton-Translocating ATPases
keywords: Iron deficiency; NMT; OsSEC24; PM-H(+)-ATPase; Rice; Tobacco