Functional Analysis of the Soybean GmCDPK3 Gene Responding to Drought and Salt Stresses

Plants have a series of response mechanisms to adapt when they are subjected to external stress. Calcium-dependent protein kinases (CDPKs) in plants function against a variety of abiotic stresses. We screened 17 CDPKs from drought- and salt-induced soybean transcriptome sequences. The phylogenetic tree divided CDPKs of rice, and soybean into five groups (I-V). -acting element analysis showed that the 17 CDPKs contained some elements associated with drought and salt stresses. Quantitative real-time PCR (qRT-PCR) analysis indicated that the 17 CDPKs were responsive after different degrees of induction under drought and salt stresses. was selected as a further research target due to its high relative expression. The subcellular localization experiment showed that GmCDPK3 was located on the membrane of mesophyll protoplasts. Overexpression of improved drought and salt resistance in . In the soybean hairy roots experiment, the leaves of hairy roots with RNA interference ( -RNAi) soybean lines were more wilted than those of overexpression ( -OE) soybean lines after drought and salt stresses. The trypan blue staining experiment further confirmed that cell membrane damage of -RNAi soybean leaves was more severe than in -OE soybean lines. In addition, proline (Pro) and chlorophyll contents were increased and malondialdehyde (MDA) content was decreased in -OE soybean lines. On the contrary, -RNAi soybean lines had decreased Pro and chlorophyll content and increased MDA. The results indicate that is essential in resisting drought and salt stresses.