Overexpression of SlUPA-like induces cell enlargement, aberrant development and low stress tolerance through phytohormonal pathway in tomato

• DOI: 10.1038/srep23818
• Publication Date: 2016-03-30T09:16:45Z
• Authors: Baolu Cui; Zongli Hu; Jingtao Hu; Yanjie Zhang; Wencheng Yin; Zhiguo Zhu; Ye Feng; Guoping Chen
• Keywords: 2. Zero hunger; 0301 basic medicine; 0303 health sciences; Dehydration; Gene Expression; Cell Enlargement; Article; 03 medical and health sciences; Linoleic Acids; Solanum lycopersicum; Plant Growth Regulators; Stress, Physiological; Plant Stomata; Disease Resistance; Plant Diseases; Plant Proteins; Signal Transduction; Transcription Factors

Abstractupa20 induces cell enlargement and hypertrophy development. In our research, overexpression of SlUPA-like, orthologous to upa20, severely affected the growth of vegetative and reproductive tissues. Wilted leaves curled upwardly and sterile flowers were found in transgenic lines. Through anatomical analysis, palisade and spongy tissues showed fluffy and hypertrophic development in transgenic plants. Gene expression analysis showed that GA responsive, biosynthetic and signal transduction genes (e.g. GAST1, SlGA20OXs, SlGA3OXs, SlGID1s and SlPREs) were significantly upregulated, indicating that GA response is stimulated by overproduction of SlUPA-like. Furthermore, SlUPA-like was strongly induced by exogenous JA and wounding. Decreased expression of PI-I and induced expression of SlJAZs (including SlJAZ2, SlJAZ10 and SlJAZ11) were observed in transgenic plants, suggesting that JA response is repressed. In addition, SlUPA-like overexpressed plant exhibited more opened stoma and higher water loss than the control when treated with dehydration stress, which was related to decreased ABA biosynthesis, signal transduction and response. Particularly, abnormal developments of transgenic plants promote the plant susceptibility to Xanthomonas campestris pv. campestris. Therefore, it is deduced from these results that SlUPA-like plays vital role in regulation of plant development and stress tolerance through GA, JA and ABA pathways.