Cotton Bsr-k1 modulates lignin deposition participating in plant resistance against Verticillium dahliae and Fusarium oxysporum

Verticillium wilt and Fusarium wilt, caused by Verticillium dahliae and Fusarium oxysporum , respectively, severely restricted cotton production. It is difficult to control the damage due to large unknown about the interaction between plants and pathogens. Here, we reported the identification of cotton Bsr-k1 , which was also designated as GhBsr-k1. The GhBsr-k1 was expressed in the root, stem and leaf. Silencing of GhBsr-k1 improved plant resistance to both V. dahliae and F. oxysporum . In the GhBsr-k1- silenced plants, the expression of phenylpropanoid metabolism related genes were significantly up-regulated comparing with the control, which resulting the increase of lignin deposition. Moreover, the expression level of PALs exhibited highly negative correlation with GhBsr-k1 . Collectively, the results suggested GhBsr-k1 acted as a negative regulator during plant resistance against V. dahliae and F. oxysporum. The potential mechanisms beyond GhBsr-k1 in plant defense may related to the regulation of the transcript of lignin deposition genes ( GhPAL2 , GhPAL5 ).