Cortical microtubule as a sensor and target of nitric oxide signal during the defence responses to Verticillium dahliae toxins in Arabidopsis

Abstract

The molecular mechanisms of signal transduction of plants in response to Verticillium dahliae (VD) are not known. Here, we show that Arabidopsis reacts to VD-toxins with a rapid burst of nitric oxide (NO) and cortical microtubule destabilization. VD-toxins treatment triggered a disruption of cortical microtubules network. This disruption can be influenced by NO production. However, cortical microtubule disruptions were not involved in regulating the NO production. The results indicated that NO may act as an upstream signalling molecule to trigger the depolymerization of cortical microtubule. Cortical microtubules may act as a target of NO signal and as a sensor to mediate the activation of PR-1 gene expression. These results suggested that NO production and cortical microtubule dynamics appeared to be parts of the important signalling system and are involved in the defence mechanisms to VD-toxins in Arabidopsis.

NO serves as a signaling intermediate downstream of H2O2to modulate dynamic microtubule cytoskeleton during responses to VD-toxins in Arabidopsis

“…18,19 Taken together, these data suggest that NO serves as a signaling intermediate downstream of H 2 O 2 to modulates the dynamic microtubule cytoskeleton during the responses to VD-toxins in Arabidopsis.…”

“…[13][14][15][16][17] We have recently demonstrated that NO and H 2 O 2 can act as an upstream signaling molecule to modulate the dynamic microtubule cytoskeleton during the defense responses to Verticillium dahliae (VD) toxins in Arabidopsis. 18 To investigate the interaction between the NO and H 2 O 2 production, wild-type seedlings were co-treated with VD-toxins plus DPI (a potent inhibitor of NADPH oxidase), DMTU (a H 2 O 2 scavenger), cPTIO (a NO scavenger) and sodium tungstate (a potent inhibitor of nitrate reductase).…”

Histone H2B Monoubiquitination Is Involved in Regulating the Dynamics of Microtubules during the Defense Response to Verticillium dahliae Toxins in Arabidopsis

“…In the previous studies, we showed that MTs play an important role in the signaling pathway for mediating the defense response against Vd toxins in Arabidopsis (Shi et al, 2009;Yao et al, 2011). Therefore, we explored whether H2Bub and the dynamics of MTs are connected during the defense response to Vd toxins.…”

“…Reduced MT dynamics have also been demonstrated to render plants less susceptible to Tobacco mosaic virus (Ouko et al, 2010). We have previously demonstrated that MTs play an important role in the defense response against Verticillium dahliae (Vd) toxins in Arabidopsis (Shi et al, 2009;Yao et al, 2011). However, the precise mechanisms regulating the dynamics and organization of the MTs remain poorly understood.…”

“…We have previously demonstrated that Vd toxins induce alterations in the cytoskeleton of an Arabidopsis cell suspension (Yuan et al, 2006) as well as that hydrogen peroxide (H 2 O 2 ) and nitric oxide may act as upstream signaling molecules to regulate cortical MT depolymerization during the defense response to Vd toxins. The depolymerization of the cortical MTs plays a functional role in the signaling pathway that mediates the expression of defense genes (Shi et al, 2009;Yao et al, 2011). However, no direct evidence exists to demonstrate the functional significance of H2Bub on the dynamics and organization of MTs in the defense response.…”