Transgenic Rice Overexperessing a Tomato Mitochondrial Phosphate Transporter, SlMPT3;1, Promotes Phosphate Uptake and Increases Grain Yield
Mitochondrial phosphate transporter plays an important regulatory role in promoting the uptake and transport of phosphate in plants. In this study, the SlMPT3;1 gene, a member of mitochondrial phosphate transporter family in tomato, was isolated and transformed into the rice Oryza sativa L. ssp. japonica cultivar Kitaake. The SlMPT3;1 is localized to the mitochondrial membrane and functions in compensating the phosphate uptake in yeast MB192 mutant that is defective in phosphate transport under Pi deficiency. RT-qPCR showed that the SlMPT3;1 is expressed in all of tomato tissues, but highly accumulated in the young leaves and stems under Pi deficiency. The data demonstrated that at least two copies of the SlMPT3;1 gene are inserted into the rice genome, and the transcripts of the SlMPT3;1 mRNA are highly accumulated in the roots of the transgenic rice. The overexpression of the SlMPT3;1 gene not only promotes phosphate uptake by the roots, but also increases the translocation of phosphate from the roots to the shoots in the transgenic rice. The transgenic rice accumulated more chlorophyll and soluble sugar in the shoots than the wild type under Pi deficiency. Microassay sequencing showed that the differentially expressed genes in the transgenic rice are mainly involved in the regulations of biological process and molecular function under Pi deficiency. Further RTqPCR analyses revealed that the differentially expressed genes, which are involved in the regulations of the biological process, cell component, and molecular function, are upregulated under Pi deficiency, and exhibit similar expression trends to the relative expression folds of these partial differentially expressed genes in the transcriptomic analyses. This study suggests that the overexpression of the SlMPT3;1 gene promoted the uptake and transport of phosphate in rice, thus leading to an enhanced increase in tiller number and effective panicle of per plant, and increasing grain yield under Pi deficiency.
KeywordsMitochondrial phosphate transporter Phosphorus deficiency Phosphate uptake SlMPT3;1 gene Transgenic rice
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- Ding W, Wang Y, Fang W, Gao S, Li X, Xiao K (2016) TaZAT8, a C2H2-ZFP type transcription factor gene in wheat, plays critical roles in mediating tolerance to Pi deprivation through regulating P acquisition, ROS homeostasis and root system establishment. Plant Physiol 158:297–311CrossRefGoogle Scholar
- Furihata T, Suzuki M, Sakurai H (1992) Kinetic characterization of two phosphate uptake systems with different affinities in suspension-cultured Catharanthus roseus protoplasts. Plant Cell Physiol 33:1151–1157Google Scholar
- Oropeza-Aburto A, Cruz-Ramirez A, Acevedo-Hernandez GJ, Perez-Torres CA, Caballero-Perez J, Herrera-Estrella L (2012) Functional analysis of the Arabidopsis PLDZ2 promoter reveals an evolutionarily conserved low-Pi-responsive transcriptional enhancer element. J Exp Bot 63:2189–2202CrossRefGoogle Scholar
- Paul EV, Sandeep S (2010) Proline Metabolism and Its Implications for Plant-Environment Interaction. The Arabidopsis Book published By American Society of Plant Biologists, November 3, e0140.10.1199/tab.0140, pp. 2-23Google Scholar
- Plaxton WC, Carswell MC (1999) Metabolic aspects of the phosphate starvation response in plants. In: Lerner R (ed) Plant responses to environmental stresses: from phytohormones to genome reorganization. Marcel Dekker, New York, pp. 349–372Google Scholar
- Stefanovic A, Ribot C, Rouached H, Wang Y, Chong J, Belbahri L, Delessert S, Poirier Y (2007) Members of the PHO1 gene family show limited functional redundancy in phosphate transfer to the shoot, and are regulated by phosphate deficiency via distinct pathways. Plant J 50:982–994CrossRefGoogle Scholar
- Wang C, Yue W, Ying Y, Wang S, Secco D, Liu Y, Whelan J, Tyerman SD, Shou H (2015) Rice SPX-Major Facility Superfamily3, a Vacuolar Phosphate Efflux Transporter, Is Involved in Maintaining Phosphate Homeostasis in Rice. Plant Physiol 169:2822–2831Google Scholar