Effect of silicon on grain yield of rice under cadmium-stress

• Published in: Acta physiologiae plantarum Vol. 38; no. 7; p. 186
• Main Authors: Lin, Hongmei, Fang, Changxun, Li, Yingzhe, Lin, Weiwei, He, Jianyu, Lin, Ruiyu, Lin, Wenxiong
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2016
• Subjects: Agriculture; Biomedical and Life Sciences; cadmium; chlorophyll; filling period; gene overexpression; genes; genetically modified organisms; grain yield; Life Sciences; Original Article; photosynthesis; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; rice; silicon; soil; transportation; Cadmium; ); Silicon; Photosynthesis; Grain yield; Rice
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-016-2177-8

Many publications indicated various beneficial effects of the addition of silicon (Si) in soil on the physiology of rice plants. The gene responsible for the Si-uptake in rice, low Si-influx 1 ( Lsi1 ), was identified and cloned for this study. The photosynthetic rate (Pn), grain yield, and resistance to Cadmium (Cd)-stress of the wild-type (WT) and Lsi1 -transgenic Lemont rice lines under Cd-stress were examined in an attempt to better understand the mechanism associated with the Si-addition, Cd-stress, and rice physiology. Si-fertilization significantly reduced the Cd-content in rice under Cd-stress. The effect was most significant in the Lsi1 -overexpression transgenic Lemont rice (Lsi1-OE line) under high Cd-stress. Conversely, Cd in soil lowered the Si-uptake of the plants indicating a significant interaction between the two elements. During the grain-filling period, Cd-stress greatly reduced the chlorophyll content and Pn of the rice resulting in a diminished grain output. However, Lsi1-OE line with a higher chlorophyll content and Pn than either WT or Lsi1 -RNAi transgenic Lemont rice (Lsi1-RNAi line) maintained a high photo-assimilate transportation for high yield potential. At harvest, Lsi1-OE line contained more Si and less Cd than WT, whereas the Lsi1-RNAi line showed an opposite result. In general, Cd-stress reduced, while Si-fertilization significantly increased, the grain yield on rice. However, no significant difference on the grain yields existed between WT and Lsi1-RNAi line. This might be due to a compensation effect generated by Lsi1-RNAi line. It appeared that Si in the soil, as well as the enhancing or inhibiting Lsi1 expression and the resistance to Cd-toxicity of the plants, could significantly affect the rice yield making alternations on these factors a plausible approach for production improvement.