BnSIP1-1 Involves in Light Response and Regulation of Endogenous Hormones and Flowering Time of Brassica Napus

BnSIP1-1 is a trihelix transcription factor family gene which functions in abiotic stress response and abscisic acid (ABA) signaling during seed germination and seedling growth of Brassica napus . In the present study, further sequence analysis and phenotype identification indicated that this gene had roles in light regulation and flowering of reproductive growth stage. Many phytohormones responsive cis -acting elements, including TC-rich repeats, GARE-motif, and TCA and TGA elements, were identified in the promoter sequence of BnSIP1-1 . The expression of BnSIP1-1 was regulated by light period and remarkable higher expression level of BnSIP1-1 was detected in roots than in leaves. Overexpression of BnSIP1-1 in Arabidopsis delayed flowering time for 3–5 days in transgenic plants. In addition, we also found BnSIP1-1 can respond to abiotic and ABA stress (treated with 200 mM NaCl, 300 mM mannitol or 50 μM ABA for 0, 1, 6, and 24 h) in B. napus through adjusting not only ABA but also other endogenous hormones, including indole-3-acetic acid and salicylic acid. Moreover, jasmonates (JA) signaling pathway was found not involving in the pathway of BnSIP1-1 responding to abiotic stresses.