JIA-2018-09

1966 WANG Ling-shuang et al. Journal of Integrative Agriculture 2018, 17(9): 1959–1971 roots was higher than that of the transgenic roots (Fig. 7-A). Without any treatments, the proline contents in both control (K599) and transgenic hairy roots were nearly the same (Fig. 7-B). Under NaCl and mannitol conditions for 7 d, proline content accumulated sharply in transgenic roots and was about one- to two-fold higher than that in control 0 2 4 6 8 10 12 14 16 18 Control A B C NaCl Relative expression RD29A WT GmBIN2 -oe 0 2 4 6 8 10 12 Control NaCl Relative expression AtCBL1 0 0.5 1.0 1.5 2.0 Control NaCl Relative expression KIN1 ** ** ** Fig. 5 Relative transcript levels of NaCl stress-responsive genes in transgenic and wild-type (WT) plants. Relative expression of RD29A , AtCBL1 , and KIN1 was examined by qRT-PCR analysis in transgenic and WT plants under normal and salt stress conditions (subjected to 100 mmol L –1 NaCl treatment for 6 h) in 14-d-old seedlings. Transcript levels were normalized against the Arabidopsis reference gene Actin8 . The data are the mean±SD of three replicates ( n =5). Asterisks indicate significant differences ( * , P <0.05; ** , P <0.01). 0 2 4 6 8 10 12 A B C K599 GmBIN2 -oe1 GmBIN2 -oe2 GmBIN2 -oe3 Relative expression Control K599 GmBIN2 -oe Control K599 GmBIN2 -oe Control K599 GmBIN2 -oe ** ** ** 0 5 10 15 20 25 K599 GmBIN2 -oe Relative root growth rate (%) NaCl Mannitol Fig. 6 Analysis the role of GmBIN2 under salt and drought stresses using the hairy roots system. A, relative GmBIN2 expression in overexpressed GmBIN2 ( GmBIN2 -oe) roots and control roots (K599) as revealed by qRT-PCR analysis. Transcript abundances were normalized against the soybean reference gene Actin4 . B, growth of control and transgenic hairy roots in root-inducing mediums with 150 mmol L –1 NaCl or 200 mmol L –1 mannitol for 1 wk. A total of 30 samples were analyzed, and the typical lines were selected to show the growth of roots. Scale bar=1 cm. C, relative growth rate of transgenic hairy roots under 150 mmol L –1 NaCl or 200 mmol L –1 mannitol for 1 wk. Values are mean±SD ( n =30). Asterisks indicate significant differences ( ** , P <0.01).