Overexpression of the MADS-box gene SlMBP21 alters leaf morphology and affects reproductive developm

• 作 者: WANG Yun-shu GUO Peng-yu ZHANG Jian-ling XIE Qiao-li SHEN Hui HU Zong-li CHEN Guo-ping
• 机 构: Laboratory of Molecular Biology of Tomato,Bioengineering College,Chongqing University,Chongqing 4000
• 出 处: 农业科学学报（英文版）
• 发表日期: 2021年12期
• 关键词: overexpression of SlMBP21 curly leaf fruit yield seed size

Fruit yield is the most important horticultural trait of tomato. SlMBP21, a SEPALLATA subclass MADS-box gene has been reported to have functions in regulating pedicel abscission zone identity and development and controlling sepal size in tomato. However, we generated transgenic tomato plants which overexpress SlMBP21 and found the transformants displayed curly leaves, abnormally shaped flowers with twisted and opened stamens, reduced yield parameters, and small and light seeds. Our studies on the gain-of-function phenotype and gene expression level showed that its novel aspects played important roles in determining leaf morphology, flower and inflorescence architecture, and seed size, as well as the fruit yield. Overexpression of SlMBP21 in tomato resulted in curly leaves with fewer leaflets due to the regulation of the critical leaf polarity genes that cause an imbalance between the midvein adaxial–abaxial cell growth. Defects in the architecture of flowers and inflorescences resulted in reduced fruit set. Furthermore, we demonstrated that SlMBP21 plays its role through inhibiting the expression of the genes involved in the determination of seed development in tomato and SlMBP21 protein can interact with other MADS-box protein (SlAGL11, TAGL1 and SlMBP3) to control seed size. Thus, these results suggest that overexpression of SlMBP21 causes multiple types of damage to plant growth and development, especially fruit yield, in tomato.