Gene Editing helps Soybean yield in the South

According to the latest news of the Chinese Academy of Agricultural Sciences, the Plant transgenic Technology Research Center of the Institute of crop Science of the Chinese Academy of Agricultural Sciences, the soybean breeding technology innovation and new variety breeding innovation team, using CRISPR/Cas9 genome editing technology to knock out the key genes of soybean flowering regulation GmFT2a and GmFT5a, to create mutant materials that are more suitable for planting at low latitudes. At the same time, the genetic effects of GmFT2a and GmFT5a genes in the regulation of soybean flowering stage were analyzed systematically, which provided new techniques and materials for the improvement of regional adaptability of soybean varieties. The related research results were recently published online in the Journal of Plant Biotechnology (PlantBiotechnologyJournal).

Han Tianfu, chief of the team and a researcher at the Research Institute of the Chinese Academy of Agricultural Sciences, said that soybean is sensitive to photoperiod, and most varieties can change from vegetative growth to reproductive growth and then blossom and bear pods only when the sunshine length is shortened to a certain limit. as a result, soybean varieties tend to late blossom and late maturity, prolong the growth period, and even cannot blossom or mature normally when they move northward. When planting to the south, it is generally shown as early flowering, shortened growth period, reduced yield or even can not grow normally. This photoperiod response characteristic makes the suitable planting area of soybean varieties generally narrow. Previous studies have shown that GmFT2a and GmFT5a genes are important flowering promoting factors in soybean.

The team constructed overexpressed plants of GmFT2a and GmFT5a genes, and used CRISPR/Cas9 genome editing technology to knock out GmFT2a and GmFT5a, combined with hybridization to create single-gene and double-gene mutant materials. The results showed that although GmFT2a and GmFT5a had complementary functions in the regulation of soybean flowering, there were great differences in flowering promotion effects between long and short days. Under the condition of short day, the flowering promoting effect of GmFT2a was stronger than that of GmFT5a, while that of GmFT5a was stronger under long day. Critical photoperiod has a great influence on the regulation of flowering stage of soybean participated by GmFT5a. Under the condition of exceeding the critical photoperiod day length of varieties, GmFT5a gene is the main flowering promoting gene and the key gene that enables soybean to adapt to long-day environment. It was also found that the created double gene mutant blossomed for an average of 57.4 days under short day conditions, which was about 31.3 days later than that of the wild type, and the plant height and node number were significantly higher than those of the wild type, as well as the number of pods and seeds per plant. This provides a new basic material for soybean variety improvement suitable for low latitudes.