title: Arabidopsis plasma membrane H+-ATPase genes AHA2 and AHA7 have distinct and overlapping roles in the modulation of root tip H+ efflux in response to low-phosphorus stress.
abstract: Phosphorus deficiency in soil is one of the major limiting factors for plant growth. Plasma membrane H+-ATPase (PM H+-ATPase) plays an important role in the plant response to low-phosphorus stress (LP). However, few details are known regarding the action of PM H+-ATPase in mediating root proton (H+) flux and root growth under LP. In this study, we investigated the involvement and function of different Arabidopsis PM H+-ATPase genes in root H+ flux in response to LP. First, we examined the expressions of all Arabidopsis PM H+-ATPase gene family members (AHA1-AHA11) under LP. Expression of AHA2 and AHA7 in roots was enhanced under this condition. When the two genes were deficient in their respective Arabidopsis mutant plants, root growth and responses of the mutants to LP were highly inhibited compared with the wild-type plant. AHA2-deficient plants exhibited reduced primary root elongation and lower H+ efflux in the root elongation zone. AHA7-deficient plants exhibited reduced root hair density and lower H+ efflux in the root hair zone. The modulation of H+ efflux by AHA2 or AHA7 was affected by the action of 14-3-3 proteins and/or auxin regulatory pathways in the context of root growth and response to LP. Our results suggest that under LP conditions, AHA2 acts mainly to modulate primary root elongation by mediating H+ efflux in the root elongation zone, whereas AHA7 plays an important role in root hair formation by mediating H+ efflux in the root hair zone.
authors.affiliation: Key Laboratory of Ministry of Education for Genetic Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.|School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Ministry of Education for Genetic Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.|School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong.|Yangzhou University, Jiangsu, China.
authors.forename: Dongping
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Ministry of Education for Genetic Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.|School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.affiliation: Key Laboratory of Ministry of Education for Genetic Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.|School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong.|Nanjing Agricultural University, Nanjing, China.
authors.forename: Feiyun
authors.initials: F
authors.lastname: Xu
authors.affiliation: Key Laboratory of Ministry of Education for Genetic Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.|School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Sheng
authors.initials: S
authors.lastname: Lin
authors.affiliation: Key Laboratory of Ministry of Education for Genetic Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.|School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Xu
authors.affiliation: Yangzhou University, Jiangsu, China.
authors.forename: Qianfeng
authors.initials: Q
authors.lastname: Li
authors.affiliation: Nanjing Agricultural University, Nanjing, China.
authors.forename: Yiyong
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Yangzhou University, Jiangsu, China.
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Liang
authors.affiliation: School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D006859:Hydrogen / Q000502:physiology*; D010758:Phosphorus / Q000172:deficiency*; D018517:Plant Roots / Q000502:physiology*; D006180:Proton-Translocating ATPases / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological
chemical_list: C545099:AHA7 protein, Arabidopsis; D029681:Arabidopsis Proteins; D010758:Phosphorus; D006859:Hydrogen; D006180:Proton-Translocating ATPases; C479903:AHA2 protein, Arabidopsis
keywords: Arabidopsis; low phosphorus; plasma membrane H+-ATPase; proton flux; root growth; root hair.