Overexpression of Arabidopsis YUCCA6 in Potato Results in High-Auxin Developmental Phenotypes and Enhanced Resistance to Water Deficit  

作　　者：Jeong Im Kim Dongwon Baek Hyeong Cheol Park Hyun Jin Chun Dong-Ha Oh Min Kyung Lee Joon-Yung Cha Woe-Yeon Kim Min Chul Kim Woo Sik Chung Hans J. Bohner Sang Yeol Lee Ray A. Bressan Shin-Woo Lee Dae-Jin Yun 

机构地区：[1]Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA [2]Division of Applied Life Science (BK21 and WCU Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University,Jinju 660-701, Republic of Korea [3]Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA [4]Department of Agronomy and Medicinal Plant Resources, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea [5]Faculty of Science, King Abdulaziz University, Jeddah 21589, KSA [6]Department of Horticulture, Purdue University, West Lafayette, IN 47907, USA

出　　处：《Molecular Plant》2013年第2期337-349,共13页分子植物（英文版）

摘　　要：Indole-3-acetic acid （IAA）, a major plant auxin, is produced in both tryptophan-dependent and tryptophan-independent pathways. A major pathway in Arabidopsis thaliana generates IAA in two reactions from tryptophan. Step one converts tryptophan to indole-3-pyruvic acid （IPA） by tryptophan aminotransferases followed by a rate-limiting step converting IPA to IAA catalyzed by YUCCA proteins. We identified eight putative StYUC （Solanum tuberosum YUCCA） genes whose deduced amino acid sequences share 50%-70% identity with those of Arabidopsis YUCCA proteins. All include canonical, conserved YUCCA sequences： FATGY motif, FMO signature sequence, and FAD-binding and NADP-binding sequences. In addition, five genes were found with -50% amino acid sequence identity to Arabidopsis trypto-phan aminotransferases. Transgenic potato （Solanum tuberosum cv. Jowon） constitutively overexpressing Arabidopsis AtYUC6 displayed high-auxin phenotypes such as narrow downward-curled leaves, increased height, erect stature, and longevity. Transgenic potato plants overexpressing AtYUC6 showed enhanced drought tolerance based on reduced water loss. The phenotype was correlated with reduced levels of reactive oxygen species in leaves. The results suggest a func-tional YUCCA pathway of auxin biosynthesis in potato that may be exploited to alter plant responses to the environment.Indole-3-acetic acid （IAA）, a major plant auxin, is produced in both tryptophan-dependent and tryptophan-independent pathways. A major pathway in Arabidopsis thaliana generates IAA in two reactions from tryptophan. Step one converts tryptophan to indole-3-pyruvic acid （IPA） by tryptophan aminotransferases followed by a rate-limiting step converting IPA to IAA catalyzed by YUCCA proteins. We identified eight putative StYUC （Solanum tuberosum YUCCA） genes whose deduced amino acid sequences share 50%-70% identity with those of Arabidopsis YUCCA proteins. All include canonical, conserved YUCCA sequences： FATGY motif, FMO signature sequence, and FAD-binding and NADP-binding sequences. In addition, five genes were found with -50% amino acid sequence identity to Arabidopsis trypto-phan aminotransferases. Transgenic potato （Solanum tuberosum cv. Jowon） constitutively overexpressing Arabidopsis AtYUC6 displayed high-auxin phenotypes such as narrow downward-curled leaves, increased height, erect stature, and longevity. Transgenic potato plants overexpressing AtYUC6 showed enhanced drought tolerance based on reduced water loss. The phenotype was correlated with reduced levels of reactive oxygen species in leaves. The results suggest a func-tional YUCCA pathway of auxin biosynthesis in potato that may be exploited to alter plant responses to the environment.

关 键 词：Solanum tuberosum POTATO Arabidopsis thaliana yuc6-1D YUCCA  StYUCCA  StTAA  auxin  drought. 

分 类 号：S482.8[农业科学—农药学] S532[农业科学—植物保护]