AS  Vol.5 No.14 , December 2014
Influence of Water Stress on the Citric Acid Metabolism Related Gene Expression in the Ponkan Fruits
Abstract: To explore the influence of water stress on fruit quality and gene expression related to citrate metabolism of ponkan. The test were conducted from May 15 to December 24 in 2013 using six-year-old ponkan (C. blanco cv. Ponkan) trees with 40% soil water conditions by taken regular watering as control. The content of acids in fruit were determined by HPLC, and relative expression of related genes of citric acid metabolic were determined by relative fluorescence quantitative PCR. The results showed that the content of citric acid, malic acid, quinic acid and total organic acids per gram sarcocarp were extremely increased by 285.2%, 320%, 480% and 299.1%, and the content of per-fruit organic acid were 77.39%, 89.64%, 117.24% and 75.9% respectively compared to those control in the fruit mature stage. Relative expression of CitCS1, CitCS2 were higher than control, and relative expression of CitAco1, CitAco2, CitAco3 had a certain increase in the late fruit development, were lower in mature stage. Three relative expression of CitIDH gene were higher than control in mature stage. Low CitGAD4 relative expression and undetectable in mature stage, the relative expression of CitGAD5 gene had a role in promoting under water stress. Furthermore, the relative expression of CitCS1, CitCS2, CitACO1, CitACO3, CitIDH1, CitIDH2, CitIDH3, CitGAD4 and CitGAD5 were influenced by water stress through the correlation analysis. Water stress caused the accumulation of citric acid, declined fruit quality, leaded to change of the genetic rela- tive expression about citric acid synthesis and degradation. The down-regulation of CitACO1, CitGAD4 and up-regulation of CitCS1, CitCS2 might be one of the reasons that promoted to the accumulation of citric acid.
Cite this paper: Zhang, G. and Xie, S. (2014) Influence of Water Stress on the Citric Acid Metabolism Related Gene Expression in the Ponkan Fruits. Agricultural Sciences, 5, 1513-1521. doi: 10.4236/as.2014.514162.

[1]   Zhou, J.Y. (2010) Molecule Physiological Basis on Genetic Differences of Carotenoid Accumulation and Ethylene Regulation in Citrus. Zhejiang University, Hangzhou.

[2]   Deng, S.X. (2009) Physiological Resistance Analysis of Citrus Plants under Deficit Irrigation Conditions. Southwest University, Chongqing.

[3]   Yamaki, Y.T. (1989) Organic Acid in the Juice of Citrus Fruits. Journal of Japan Horticultural Science Society, 58, 587-594.

[4]   Li, Y.Z. (1997) Research Progress on Citrus Fruit Acid Metabolism a Literature Review. Sichuan Fruits, 4, 17-19.

[5]   Sun, X.H., Xiong, J.J., Zhu, A.D., Zhang, L., Ma, Q.L., Xu, J., Cheng, Y.J. and Deng, X.X. (2012) Sugars and Organic Acids Changes in Pericarp and Endocarp Tissues of Pumelo Fruit during Postharvest Storage. Scientia Horticulturae, 142, 112-117.

[6]   Chen, M., Xie, X.L., Lin, Q., Chen, J.Y., Donald, G., Yin, X.R., Sun, C.D. and Chen, K.S. (2013) Differential Expression of Organic Acid Degradation-Related Genes during Fruit Development of Navel Oranges (Citrus sinensis) in Two Habitats. Plant Molecular Biology Reporter, 31, 1131-1140.

[7]   Tadeo, F.R., Cercós, M., Colmenero-Flores, J.M., Iglesias, D.J., Naranjo, M.A., Rios, G., Carrera, E., Ruiz-Rivero, O., Lliso, I., Morillon, R., Ollitrault, P. and Talon, M. (2008) Molecular Physiology of Development and Quality of Citrus. Advances in Botanical Research, 47, 147-223.

[8]   Anyia, A.O. and Herzog, H. (2004) Water-Use Efficiency, Leaf Area and Leaf Gas Exchange of Cowpeas under Mid-Season Drought. European Journal of Agronomy, 20, 327-339.

[9]   Xie, S.X., Liu, Q., Xiong, X.Y., Zhang, Q.M. and Lovatt, C.J. (2011) Influences of Water Stress on Citrus Photosynthesis Characteristic and Cell Ultra-Structure. Acta Agriculturae Universitatis Jiangxiensis, 32, 234-238.

[10]   Nie, Q., Lu, X.P., Zhao, X.-L. and Xie, S.X. (2013) ABA Production and Expression Analysis of Its Key Genes in Newhall Navel Orange and Satsuma Mandarin under Water Stress. Journal of Fruit Science, 30, 348-353.

[11]   Zhao, X.L., Lu, X.P., Nie, Q., Huang, C.N., Xiao, Y.M. and Xie, S.X. (2013) Effect of Water Stress on Physiological Characteristics, JA Biosynthesis and Correlative Genes Expression in Citrus. Acta Agriculturae Universitatis Jiangxiensis, 35, 530-535.

[12]   Wang, H.B., Li, L.G., Chen, X.S., Li, H.F., Yang, J.M., Liu, J.F. and Wang, C. (2010) Flavor Compounds and Flavor Quality of Fruits of Mid-Season Apple Cultivars. Scientia Agricultura Sinica, 43, 2300-2306.

[13]   Luo, A.C., Yang, X.H., Deng, Y.Y., Li, C.F., Xiang, K.S. and Li, D.G. (2003) Organic Acid Concentrations and the Relative Enzymatic Changes during the Development of Citrus Fruits. Scientia Agricultura Sinica, 36, 941-944.

[14]   Sadka, A., Artzi, B., Cohen, L., Dahan, E., Hasdai, D., Tagari, E. and Erner, Y. (2000) Arsenite Reduces Acid Content in Citrus Fruit, Inhibits Activity of Citrate Synthase but Induces Its Gene Expression. Journal of the American Society for Horticultural Science, 125, 288-293.

[15]   Cercós, M., Soler, G., Iglesias, D.J., Gadea, J., Forment, J. and Talón, M. (2006) Global Analysis of Gene Expression during Development and Ripening of Citrus Fruit Flesh. A Proposed Mechanism for Citric Acid Utilization. Plant Molecular Biology, 62, 513-527.

[16]   Wen, T., Xiong, Q.E., Zeng, W.G. and Liu, Y.P. (2001) Changes of Organic Acid Synthetase Activity during Fruit Development of Navel Orange (Citrus sinesis Osbeck). Acta Horticulturae Sinica, 28, 161-163.

[17]   Canel, C., Bailey Serres, J.N. and Roose, M.L. (1996) Molecular Characterization of the Mitochondrial Citrate Synthase Gene of an Acidless Pummelo (Citrus maxima). Plant Molecular Biology, 31, 143-147.

[18]   Kubo, T., Kihara, T. and Hirabayashi, T. (2002) The Effects of Spraying Lead Arsenate on Citrate Accumulation and the Related Enzyme Activities in the Juice Sacs of Citrus natsudaidai. Journal of the Japanese Society for Horticultural Science, 71, 305-310.

[19]   Yu, K.Q., Xu, Q., Da, X.L., Guo, F., Ding, Y.D. and Deng, X.X. (2012) Transcriptome Changes during Fruit Development and Ripening of Sweet Orange (Citrus sinensis). BMC Genomics, 13, 10.

[20]   Terol, J., Soler, G., Talon, M. and Cercos, M. (2010) The Aconitate Hydratase Family from Citrus. BMC Plant Biology, 10, 222.

[21]   Aprile, A., Federici, C., Close, T.J., Bellis, L., Cattivelli, L. and Roose, M.L. (2011) Expression of the H+-ATPase AHA10 Proton Pump Is Associated with Citric Acid Accumulation in Lemon Juice Sac Cells. Functional & Integrative Genomics, 11, 551-563.