Molecular Cloning, Expression Profiles And OfFunctional Analysis GmMFT Gene In Soybean (Glycine Max)

MFT (MOTHER OF FT AND TFL1) is a member of phosphatidylethanolamine-binding protein(PEBP)gene family and evolutionarily conserved in a wide range of multicellular land plants. MFT wasinitially identified as a floral regulator in some research. However, later studies using expressionanalysis and transformation analysis of MFT genes indicated that MFT genes may function in seeddevelopment or germination rather than in flowering. An analysis of MFT genes aimed to clarify theirdefinite roles in seed development or germination may be helpful to improve the quality of seeds at themolecular level. In this study, GmMFT gene was cloned and bioinfomatically analyzed. Itsspatio-temporal expression profiles across different developmental stages and in various tissues/organswere performed using real-time quantitative PCR (RT-qPCR). Furthermore, functional analysis ofGmMFT gene was performed in transgenic Arabidopsis. At the same time, due to selection of properinternal reference genes is critical for the reliable RT-qPCR results, we evaluated the expressionstability of18candidate reference genes in34different seed samples in order to study the expressionpattern of GmMFT gene during seed development and germination. The main results were as follows:1. The reference genes identified as optimums for soybean seed development were TUA5andUKN2, whereas for seed germination were Glyma05g37470and Glyma08g28550. Furthermore, fortotal samples it was necessary to combine four genes of Glyma05g37470, Glyma08g28550,Glyma18g04130, and UKN2for normalization.2. In soybean, GmMFT gene mainly expressed in seeds and the expression level was increasingduring seed development, whereas decreasing during seed germination. This expression pattern ofGmMFT gene indicated that GmMFT may function in seed development or germination of soybean.3. GmMFT protein was localized in both nuclear and cytoplasm as Arabidopsis AtMFT and wheatTaMFT, indicating it may be a transcription factor.4. The phenotype analysis of transgenic Arabidopsis indicated that GmMFT gene may suppressesseed germination rather than regulate flowering or seed development. In comparison of the expressionof germination-related genes between GmMFT transgenic and wild-type seeds, We found that GmMFTgene may inhibit seed germination in two ways: On one hand, GmMFT promotes the accumulation ofABA in seeds by increasing the expression of ABA biosynthetic genes and decreasing the expression ofABA degradation genes; On the other hand, GmMFT inhibits the accumulation of GA in seeds bydecreasing the expression of GA biosynthetic genes and increasing the expression of GA degradationgenes.