Benzothiadiazole (BTH) is really a so-called plant activator and protects plants
Benzothiadiazole (BTH) is really a so-called plant activator and protects plants from diseases by activating the salicylic acid (SA) signaling pathway. signaling in rice and its potential utility in improving disease resistance of rice, an importance food resource worldwide. INTRODUCTION Plants respond to microbial pathogen attack by activating a variety of defense responses that are mediated through multiple signaling pathways. In many dicot plants, salicylic acid (SA) plays a crucial role in mediating one of the signaling pathways leading to defense responses, including induction of (genes and the onset of disease resistance (Malamy et al., 1990; Mtraux et al., 1990; Rasmussen et al., 1991). Exogenous application of SA induces gene expression and disease resistance in dicots. In contrast with dicots, which contain low basal levels of SA, rice has basal levels of SA two orders of magnitude 4SC-202 supplier higher (Raskin et al., 1990). SA levels do not increase after inoculation of rice with either the bacterial pathogen or the fungal pathogens and (Silverman et al., 1995). By contrast, 4SC-202 supplier SA levels in the leaves of 28 rice ((Rohilla et al., 2002) and (Schweizer et al., 1999) and is used in the field, but the molecular mechanisms underlying its action remain to be investigated. In dicots, several regulatory proteins have been implicated in the transcriptional regulation of defense genes under the control of the SA signaling pathway. Among those is NPR1, an important positive regulator in this pathway that is required for transducing the SA signal to downstream gene activation (Cao et al., 1997). Chern et al. (2001) have reported that overexpression of NPR1 in rice enhances resistance to NPR1 interacts with the bZIP-type transcription factors (TFs) of rice, as in (Chern et al., 2001). Those investigators have shown that NH1, a rice ortholog of NPR1, also interacts with a bZIP-type TF in rice and Rabbit Polyclonal to JAK1 (phospho-Tyr1022) that NH1 overexpression in rice confers high levels of resistance to (Chern et al., 2005). These observations suggest that rice has a signaling pathway for disease resistance that is similar to the SA-dependent pathway in dicots. The WRKY family of TFs has been suggested to play a role in controlling the transcription of defense genes through the W-box in their promoters, which is a key genes 4SC-202 supplier are expressed in response to pathogen infection (Kalde et al., 2003), and the function of several WRKY TFs has been implicated in the defense reactions in (Yu et al., 2001; Chen and Chen, 2002; Robatzek and Somssich, 2002). An group III WRKY TF, WRKY70, activates SA-regulated genes downstream of and represses jasmonic acid (JA)Cresponsive genes, integrating SA and JA signaling during systemic acquired resistance (Li et al., 2004). Recent studies have placed several WRKY TFs, including At mutant plants (Wang et al., 2006). Based on chromatin immunoprecipitation experiments in parsley ((Journot-Catalino et al., 2006; Wang et al., 2006; Xu et al., 2006). The WRKY TFs form a superfamily in rice, as in dicots (Xie et al., 2005). Several genes are expressed in response to the rice blast fungal elicitor (Kim et al., 2000), 4SC-202 supplier infection with causal agents of bacterial blight and fungal blast diseases (Wen et al., 2003; Ryu et al., 2006), and defense signal molecules SA and JA (Ryu et al., 2006). Os WRKY03 (Liu et al., 2005) and Os WRKY71 (Liu et al., 2006) were functionally characterized, and both were placed upstream of NH1. However, our knowledge of the functions of WRKY TFs in the defense programs in grain is limited. So that they can elucidate the molecular systems fundamental BTH-induced disease level of resistance, we determined knockdown grain plants, and overexpression of improved level of resistance, indicating that WRKY TF performs a crucial.