title: The mitochondrial malate dehydrogenase 1 gene GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton.
abstract: Cotton, an important commercial crop, is cultivated for its natural fibers, and requires an adequate supply of soil nutrients, including phosphorus, for its growth. Soil phosporus exists primarily in insoluble forms. We isolated a mitochondrial malate dehydrogenase (MDH) gene, designated as GhmMDH1, from Gossypium hirsutum L. to assess its effect in enhancing P availability and absorption. An enzyme kinetic assay showed that the recombinant GhmMDH1 possesses the capacity to catalyze the interconversion of oxaloacetate and malate. The malate contents in the roots, leaves and root exudates was significantly higher in GhmMDH1-overexpressing plants and lower in knockdown plants compared with the wild-type control. Knockdown of GhmMDH1 gene resulted in increased respiration rate and reduced biomass whilst overexpression of GhmMDH1 gave rise to decreased respiration rate and higher biomass in the transgenic plants. When cultured in medium containing only insoluble phosphorus, Al-phosphorus, Fe-phosphorus, or Ca-phosphorus, GhmMDH1-overexpressing plants produced significantly longer roots and had a higher biomass and P content than WT plants, however, knockdown plants showed the opposite results for these traits. Collectively, our results show that GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton, owing to its functions in leaf respiration and P acquisition.
authors.affiliation: 1] The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China [2] Institute of Cotton Research, Shanxi Agricultural Academy of Science, Yuncheng, 044000, China.
authors.forename: Zhi-An
authors.initials: ZA
authors.lastname: Wang
authors.affiliation: The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: The State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China.
authors.forename: Xiao-Yang
authors.initials: XY
authors.lastname: Ge
authors.affiliation: The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Chun-Lin
authors.initials: CL
authors.lastname: Yang
authors.affiliation: Institute of Cotton Research, Shanxi Agricultural Academy of Science, Yuncheng, 044000, China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Luo
authors.affiliation: Institute of Cotton Research, Shanxi Agricultural Academy of Science, Yuncheng, 044000, China.
authors.forename: An-Hong
authors.initials: AH
authors.lastname: Zhang
authors.affiliation: Institute of Cotton Research, Shanxi Agricultural Academy of Science, Yuncheng, 044000, China.
authors.forename: Juan-Li
authors.initials: JL
authors.lastname: Xiao
authors.affiliation: The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Ying-Chuan
authors.initials: YC
authors.lastname: Tian
authors.affiliation: The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Gui-Xian
authors.initials: GX
authors.lastname: Xia
authors.affiliation: The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Chen
authors.affiliation: The State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China.
authors.forename: Fu-Guang
authors.initials: FG
authors.lastname: Li
authors.affiliation: The State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Jia-He
authors.initials: JH
authors.lastname: Wu
mesh_terms: D018533:Biomass; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques; D017343:Genes, Plant; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008291:Malate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology*; D010758:Phosphorus / Q000172:deficiency*; D018517:Plant Roots / Q000254:growth & development*; D030821:Plants, Genetically Modified; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D010758:Phosphorus; D008291:Malate Dehydrogenase