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 Our group mainly focuses on engineering salt- and drought-tolerant plants and molecular analyses of mechanisms underlying plant responses towards salinity and desiccation, which includes cloning and modification of genes responsible for salt and drought tolerance, isolation and characterization of their regulation regions as well as genetic transformation of salt-tolerant plants.
Principal Investigator: Dr. Hong-Xia Zhang, Professor. Email: hxzhang@sippe.ac.cn
Staff: Dr. Hua Liu, Research Assistant; Dr. Cui-Ting Wang, Research Assistant; Dr. Bei Li, Research Assistant; Yu-Ting Wu, Research Intern
Graduate Students: Qun-Dan Lv; Hong-Tao Li; Ren-Jie Tang; Qiang Zhu; Jian-Tao Zhang; Yan-Mei Hu; Yan Bao; Qi Liu
Graduated Students: Yue Zhang, 2003 (PhD); Yue-Feng Guan, 2006 (PhD); Jiang Zhang, 2004 (PhD); Qiu-Qing Wang, 2004 (MS)
Transgenic Salt-tolerant Sugar Beet (Beta vulgaris L.) Plants Constitutively Expressing an Arabidopsis thaliana Vacuolar Na+/H+ Antiporter Gene, AtNHX3, Accumulate More Soluble Sugar but Less Salt in Storage Roots
Salinity is one of the most significant abiotic stresses which severely affect the agricultural production worldwide. Generally, plants are thought to remove Na+ from the cytoplasm by transporting it into the vacuolar using Na+/H+ exchangers localized in the vacuolar. In the glycophytic model plant Arobidopsis thaliana, eight membranes of vacuolar Na+/H+ antiporter gene (AtNHX) have been isolated. In this study, we investigated the function of AtNHX3 and overexpressed it in sugar beet (Beta vulgaris L.). Transgenic lines were used for further molecular and physiological determination.
1. By mediation of Agrobacterium, we got the transgenic lines, and found that AtNHX3 was successfully integrated into the transgenic plant genomes. After the treatment of different NaCl (0-500mmol/L) concentrations, transgenic plants were able to grow in the presence of 500mM NaCl, but wild type plants failed to survive. And the other results such as the dry and fresh weight, the content of Na+/K+, proline and relative conduction showed that ectopic expression of AtNHX3 in sugar beet conferred salt tolerance on transgenic plants.
2. We also detected the contents of glucose, frucrose, sucrose and total soluble sugar in transgenic plants and wild type plants grown under saline condition. Transgenic plants produced more sucrose than wild type.
3. AtNHX3 may be involved in K+ transport.
Taken together, our results indicated that constitutive expression of AtNHX3 in sugar beet increased salt tolerance of the transgenic plants.
Major Publications:
Yang L, Tang RJ, Zhu JQ, Liu H, Mueller-Roeber B, Xia HJ and Zhang HX. (2008) Enhancement of stress tolerance in transgenic tobacco plants constitutively expressing AtIpk2β, an inositol polyphosphate 6-/3-kinase from Arabidopsis thaliana. Plant Mol Biol. 66: 329-343. Zhang J, Tan W, Yang XH and Zhang HX. (2008) Plastid-expressed choline monooxygenase gene improves salt and drought tolerance through accumulation of glycine betaine in tobacco. Plant Cell Rep. 27: 1113-1124. Guan YF, Huang XY, Zhu J, Gao JF, Zhang HX and Yang ZN. (2008) RUPTURED POLLEN GRAIN1, a member of the MtN3/saliva gene family, is crucial for exine pattern formation and cell integrity of microspores in Arabidopsis. Plant Physiol. 147: 852-863. Liu H, Wang QQ, Yu MM, Zhang YY, Wu YB and Zhang HX. (2008) Transgenic salt-tolerant sugar beet (Beta vulgaris L.) constitutively expressing an Arabidopsis thaliana vacuolar Na+/H+ antiporter gene, AtNHX3, accumulates more soluble sugar but less salt in storage roots. Plant Cell Environ 31: 1325-1334.
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