Light Induce Effect On Glycoalkaloids Accumulation In Potato (Solanum Tubersum) Tuber

Potato tubers steroidal glycoalkaloids (SGAs) affected the palatability and food safety, at the same time, potato tubers of steroidal glycoalkaloids was accumulated due to genetic and environmental factors, especially post-harvest storage conditions. The inducing effect of light on SGAs was most obvious in various factors of the environment, but inducing effect of different light qualities on the SGAs and light signal on the biosynthesis of SGAs were still unknown.In this study,9 potato genotypes were selected as experimental materials, study on the inducing effects of different light qualities and light signal transduction molecules, further analysis of light signal induced synthesis mechanism on SGAs in potato tubers, provided a theoretical basis for the molecular level to regulate the accumulation on SGAs in potato tuber. Main results are displayed as follows:(1) Different light-sensitive levels of four potato varieties (Zhuangshu No.3, Weishu No.1, Atlantic and Shepody) were selected as experimental materials, Steroidal glycoalkaloids content in potato tuber was studied in different optical qualities. The results showed that steroidal glycoalkaloids content was different in potato tubers in different light qualities. Red light (630 nm) inducing effect was most obvious, bule light took the second place, under the treatment of orange light, yellow light, and green light, the accumulation of steroidal glycoalkaloids in potato tubers was not obvious, the treatment of purple light did not cause the accumulation of steroidal glycoalkaloids in potato tubers. The same light quality affected differently on different varieties of potato tuber of steroidal glycoalkaloids,and it was showed that light-induced accumulation of SGAs of potato tubers ralated with the genetic composition of the potato varieties.(2) Potato genotypes of five different skin colors (white, purple, red, purple-red and pink) were selected as experimental materials.The sensitivity of different potato skins which was influenced by different diffferent light qualities were studied.The results showed that the sensitivity of potato tuber of differedt skin colors was influenced obviously by different light qualities, potato tuber skin color deeper SGAs accumulated more, and red light was still the most effective light quality for inducing SGAs accumulation in all potato skins, followed by blue light.(3) Different sensitivities of potato tubers and light signal transduction molecules were studied by four diffrenent light qualities (red, blue, white and dark), the results showed that the content of the second messenger's—calmodulin and the G protein of potato tubers treated with red light increased more obvious than other potato tubers treated with blue light, white light, and darkness,but cAMP content was very low and unstable. It was inferred that the light was the signal molecule for SGAs accumulation, which stimulated the second messenger G protein and calmodulin, participate in accumulation of SGAs in potato tubers.