Soybean (glycine Max (l.) Merr.) Implicit The Anthocyanidin Function

Cryptochromes are blue light receptors in plants and animals, which are firstly found in Arabidopsis. Plants have at least three types of cryptochromes: cryptochrome 1 (CRY1), cryptochrome 2 (CRY2) and cryptochrome 3 (CRY3). In Arabidopsis, CRY1 and CRY2 primarily mediate the blue light inhibition of hypocotyl elongation and the photoperiodic promotion of floral initiation, respectively. In addition to Arabidopsis, cryptochromes have also been found in other higher plants, tomato, rapeseed, pea, and rice, and in lower plants, such as algae, moss, fern. Results of these studies indicate that cryptochromes regulate developmental aspects in angiosperms in a way similar to that in Arabidopsis. In this research we cloned two soybean cryptochromes, GmCRY1a and GmCRY2a Based on the sequences of GmCRY1a and GmCRY2a, we identified 4 GmCRY1 and 2 GmCRY2 apoproteins in soybean genome sequences. We then focused on GmCRY1a and GmCRY2a. We found three expression characteristics of GmCRY1a and GmCRY2a, nuclei localization, degradation of GmCRY2a in blue light, and higher level of expression in younger leaves, among which the first and second ones are similar to that in Arabidopsis but the third is a novel one in soybean. We also detected the functions of them and found that they have the similar functions as their orthologs in Arabidopsis, but GmCRY1a shows more primary role in not only blue light inhibition of hypocotyl elongation but also photoperiodic promotion of floral initiation than GmCRY2a does. We next checked the daily rhythm of soybean cryptochromes' expression and found that the mRNA expression of both genes and only GmCRY1a's protein but not GmCRY2a's protein showed circadian rhythm. These protein changes are just the reverse to that in Arabidopsis. To confirm the fact that GmCRY1a can promote flowering, we tested the flowering time of 11 soybean cultivars and 328 wild soybeans ranging in different latitudes from～25 to～50°N and found that there is strong and clear correlation between the flowering time and latitudes. We also found the strong and clear correlation between the flowering time and/or latitudes and the expression of GmCRY1a protein in these 11 cultivars, suggesting that the circadian rhythmic expression of GmCRY1a is related to that the latitudinal cline in flowering of soybean.