title: Increased salt tolerance with overexpression of cation/proton antiporter 1 genes: a meta-analysis.
abstract: Cation/proton antiporter 1 (CPA1) genes encode cellular Na+/H+exchanger proteins, which act to adjust ionic balance. Overexpression of CPA1s can improve plant performance under salt stress. However, the diversified roles of the CPA1 family and the various parameters used in evaluating transgenic plants over-expressing CPA1s make it challenging to assess the complex functions of CPA1s and their physiological mechanisms in salt tolerance. Using meta-analysis, we determined how overexpression of CPA1s has influenced several plant characteristics involved in response and resilience to NaCl stress. We also evaluated experimental variables that favour or reduce CPA1 effects in transgenic plants. Viewed across studies, overexpression of CPA1s has increased the magnitude of 10 of the 19 plant characteristics examined, by 25% or more. Among the ten moderating variables, several had substantial impacts on the extent of CPA1 influence: type of culture media, donor and recipient type and genus, and gene family. Genes from monocotyledonous plants stimulated root K+, root K+/Na+, total chlorophyll, total dry weight and root length much more than genes from dicotyledonous species. Genes transformed to or from Arabidopsis have led to smaller CPA1-induced increases in plant characteristics than genes transferred to or from other genera. Heterogeneous expression of CPA1s led to greater increases in leaf chlorophyll and root length than homologous expression. These findings should help guide future investigations into the function of CPA1s in plant salt tolerance and the use of genetic engineering for breeding of resistance.
authors.affiliation: Institute of Horticulture, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Nanjing, Jiangsu, China.|College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, China.|Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA.
authors.forename: Yuan-Chun
authors.initials: YC
authors.lastname: Ma
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Augé
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Dong
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, China.|Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA.
authors.forename: Zong-Ming Max
authors.initials: ZM
authors.lastname: Cheng
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D017920:Antiporters / Q000096:biosynthesis / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011522:Protons; D055049:Salt Tolerance / Q000187:drug effects*; D055051:Salt-Tolerant Plants / Q000235:genetics* / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics
chemical_list: D017920:Antiporters; D011522:Protons; D012965:Sodium Chloride
keywords: CPA1 gene family; antiporter; meta-analysis; overexpression; salt tolerance; transgenic