The NAC (NAM, ATAF1/2 and CUC2) transcription factor family plays a key role in plant development and responses to abiotic stress.  GmNAC15 (Glyma15g40510.1), a member of the NAC transcription factor family in soybean, was functionally characterized, especially with regard to its role in salt tolerance.  In the present study, qRT-PCR (quantitative reverse transcription PCR) analysis indicated that GmNAC15 was induced by salt, drought, low temperature stress, and ABA treatment in roots and leaves.  GmNAC15 overexpression in soybean (Glycine max) hairy roots enhanced salt tolerance.  Transgenic hairy roots improved the survival of wild leaves; however, overexpression of GmNAC15 in hairy root couldn’t influnce the expression level of GmNAC15 in leaf.  GmNAC15 regulates the expression levels of genes responsive to salt stress.  Altogether, these results provide experimental evidence of the positive effect of GmNAC15 on salt tolerance in soybean and the potential application of genetic manipulation to enhance the salt tolerance of important crops. 

Wheat grain natural transverse sections of 12 periods were observed and analyzed using scanning electron micrographs technology and Bio-Quant system IV image analyzer in order to detect the developing process of A- and B-type starch granules. In addition, the chemical composition and starch granule-bound proteins (SGPs) of A- and B-type starch granules were tested and analyzed. The results showed that A-type starch granules in wheat began from 3 d post anthesis (DPA) till grain maturing and B-type starch granules occured after 15 DPA till grain maturing. Approximately 98.5% of chemical compositions in both A- and B-type starch granules were amylose and amylopectin, and more than half of which were amylopectin. The amylopectin contents, average chain length, and chain length distribution (degree of polymerization> 40) of amylopectin in A-type starch granules were significant higher than that of B-type starch granules. SGP-145, SGP- 140, and SGP-26 kD were associated with A-type starch formation in wheat grain.