Guodong Chen1, Qian Chen1, Kaijie Qi1, Zhihua Xie1, Hao Yin1, Peng Wang1, Runze Wang1, Zhi Huang1, Shaoling Zhang1, Li Wang2, Juyou Wu3. 1. Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. 2. Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. lwang@njau.edu.cn. 3. Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. juyouwu@njau.edu.cn.
Abstract
MAIN CONCLUSION: PbrKAT1, which is inhibited by external Na+ in Xenopus laevis oocytes, is characterized as encoding a typical inward rectifying channel that is mainly expressed in guard cells. Potassium (K+) is the most abundant cation in plant cells necessary for plant growth and development. The uptake and transport of K+ are mainly completed through transporters and channels, and the Shaker family genes are the most studied K+ channels in plants. However, there is far less information about this family in Rosaceae species. We performed a genome-wide analysis and identified Shaker K+ channel gene family members in Rosaceae. We cloned and characterized a Shaker K+ channel KAT1 from pear (Pyrus × bretschneideri). In total, 36 Shaker K+ channel genes were identified from Rosaceae species and were classified into five subgroups based on structural characteristics and a phylogenetic analysis. Whole-genome and dispersed duplications were the primary forces underlying Shaker K+ channel gene family expansion in Rosaceae, and purifying selection played a key role in the evolution of Shaker K+ channel genes. β-Glucuronidase and qRT-PCR assays revealed that PbrKAT1 was mainly expressed in leaves, especially in guard cells. PbrKAT1 displayed a typical inward-rectifying current when expressed in Xenopus laevis oocytes. The activity of PbrKAT1 was inhibited by external sodium ions, possibly playing an important role in the regulation of salt tolerance in pear. These results provide valuable information on evolution, expression and functions of the Shaker K+ channel gene family in plants.
MAIN CONCLUSION: PbrKAT1, which is inhibited by external Na+ in Xenopus laevis oocytes, is characterized as encoding a typical inward rectifying channel that is mainly expressed in guard cells. Potassium (K+) is the most abundant cation in plant cells necessary for plant growth and development. The uptake and transport of K+ are mainly completed through transporters and channels, and the Shaker family genes are the most studied K+ channels in plants. However, there is far less information about this family in Rosaceae species. We performed a genome-wide analysis and identified Shaker K+ channel gene family members in Rosaceae. We cloned and characterized a Shaker K+ channel KAT1 from pear (Pyrus × bretschneideri). In total, 36 Shaker K+ channel genes were identified from Rosaceae species and were classified into five subgroups based on structural characteristics and a phylogenetic analysis. Whole-genome and dispersed duplications were the primary forces underlying Shaker K+ channel gene family expansion in Rosaceae, and purifying selection played a key role in the evolution of Shaker K+ channel genes. β-Glucuronidase and qRT-PCR assays revealed that PbrKAT1 was mainly expressed in leaves, especially in guard cells. PbrKAT1 displayed a typical inward-rectifying current when expressed in Xenopus laevis oocytes. The activity of PbrKAT1 was inhibited by external sodium ions, possibly playing an important role in the regulation of salt tolerance in pear. These results provide valuable information on evolution, expression and functions of the Shaker K+ channel gene family in plants.
Authors: Steven Maere; Stefanie De Bodt; Jeroen Raes; Tineke Casneuf; Marc Van Montagu; Martin Kuiper; Yves Van de Peer Journal: Proc Natl Acad Sci U S A Date: 2005-03-30 Impact factor: 11.205