A wheat cytochrome P450 enhances both resistance to deoxynivalenol and grain yield

Abstract

The mycotoxin deoxynivalenol (DON) serves as a plant disease virulence factor for the fungi Fusarium graminearum and F. culmorum during the development of Fusarium head blight (FHB) disease on wheat. A wheat cytochrome P450 gene from the subfamily CYP72A, TaCYP72A, was cloned from wheat cultivar CM82036. TaCYP72A was located on chromosome 3A with homeologs present on 3B and 3D of the wheat genome. Using gene expression studies, we showed that TaCYP72A variants were activated in wheat spikelets as an early response to F. graminearum, and this activation was in response to the mycotoxic Fusarium virulence factor deoxynivalenol (DON). Virus induced gene silencing (VIGS) studies in wheat heads revealed that this gene family contributes to DON resistance. VIGS resulted in more DON-induced discoloration of spikelets, as compared to mock VIGS treatment. In addition to positively affecting DON resistance, TaCYP72A also had a positive effect on grain number. VIGS of TaCYP72A genes reduced grain number by more than 59%. Thus, we provide evidence that TaCYP72A contributes to host resistance to DON and conclude that this gene family warrants further assessment as positive contributors to both biotic stress resistance and grain development in wheat.

The modulation of stomatal conductance and photosynthetic parameters is involved in Fusarium head blight resistance in wheat

“…Hence, the induction of CYP450 by F. graminearum in the resistant wheat genotype might denote a resistant physiological mechanism to FHB toxic metabolites, such as the mycotoxin DON. This hypothesis was confirmed by several studies demonstrating that CYP450s were able to detoxify DON in vitro [74] and in vivo [73]. De Zutter et al (2017) investigated plant-response in wheat ears to a combined attack of F. graminearum and aphids and observed that PR1 and PR2, the latter encoding a β-1,3-glucanase, were consistently up-regulated [75].…”

“…Much evidence supported our results indicating that the CYP450 gene family plays an active role in wheat resistance against F. graminearum and DON. In actual fact, strong CYP450 PLOS ONE accumulations were found in resistant but not in susceptible wheat cultivars challenged with F. graminearum and DON [72,73]. CYP450s are involved in the detoxification of xenobiotic substances.…”

TaUGT6, a Novel UDP-Glycosyltransferase Gene Enhances the Resistance to FHB and DON Accumulation in Wheat

“…Silencing of the ethylene insensitive 2 gene in wheat resulted in FHB resistance and gain of function related to gibberellic acid-sensitive DELLA NIL lines that showed more resistance to the Fusarium -infected spikes and reduced DON-induced cell death rate ( Chen et al, 2009 ; Saville et al, 2012 ). Enzymes involved in diverse processes have been shown to enhance DON resistance, e.g., the wheat cytochrome P450 TaCYP72A, which contributes to DON host resistance and bacterial cytochrome P450 Ddna , which can convert DON to 16-hydroxy-DON ( Ito et al, 2013 ; Gunupuru et al, 2018 ). UDP-glycosyltransferases (UGTs) are the most widely studied enzymes that have been shown to confer DON and FHB resistance via conjugation of DON to DON-3-O-glucoside (D3G).…”

Hybrid Genome Assembly of a Major Quantitative Disease Resistance Locus in Soybean Toward Fusarium graminearum

“…Fusarium graminearum is more commonly known to cause disease in wheat and corn, and because of this, more is known about the mechanisms of resistance in these systems. Specifically in wheat, a cytochrome P450 is known to be highly expressed during early infection by F. graminearum in Fusarium head blight and deoxynivalenol (DON)‐resistant cultivars, and it is also known that this gene family contributes to DON resistance, a mycotoxin produced by F. graminearum (Gunupuru et al, 2018). Interestingly, a gene encoding a cytochrome P450 gene has also been characterized in a major QDRL in corn and was found to have higher expression in the resistant inbred line.…”