Cotton WATs Modulate SA Biosynthesis and Local Lignin Deposition Participating in Plant Resistance Against Verticillium dahliae

Abstract

Verticillium wilt, caused by Verticillium dahliae , seriously limits cotton production. It is difficult to control this pathogen damage mainly due to the complexity of the molecular mechanism of plant resistance to V. dahliae . Here, we identified three homologous cotton Walls Are Thin ( WAT ) genes, which were designated as GhWAT1, GhWAT2 , and GhWAT3. The GhWATs were predominantly expressed in the roots, internodes, and hypocotyls and induced by infection with V. dahliae and treatment with indole-3-acetic acid (IAA) and salicylic acid (SA). GhWAT1 -, GhWAT2 -, or GhWAT3 -silenced plants showed a comparable phenotype and level of resistance with control plants, but simultaneously silenced three GhWATs ( GhWAT123 -silenced), inhibited plant growth and increased plant resistance to V. dahliae , indicating that these genes were functionally redundant. In the GhWAT123 -silenced plants, the expression of SA related genes was significantly upregulated compared with the control, resulting in an increase of SA level. Moreover, the histochemical analysis showed that xylem development was inhibited in GhWAT123 -silenced plants compared with the control. However, lignin deposition increased in the xylem of the GhWAT123 -silenced plants compared to the control, and there were higher expression levels of lignin synthesis- and lignifications-related genes in the GhWAT123 -silenced plants. Collectively, the results showed that GhWATs in triple-silenced plants acts as negative regulators of plant resistance against V. dahliae. The potential mechanism of the WATs functioning in the plant defence can modulate the SA biosynthesis and lignin deposition in the xylem.

Heterologous Expression of the AtNPR1 Gene in Olive and Its Effects on Fungal Tolerance

“…In potato, overexpression of a polymorphic sequence of cDNA-AFLP, StoNPR1, isolated from a Verticillium-resistant genotype of Solanum torvum (Wang et al, 2010), conferred resistance through induction of genes involved in the SA biosynthetic pathway, including ICS1 (isochorismate synthase 1) (Deng-Wei et al, 2014). Similarly, in cotton, Gong et al (2017) reported that decreased resistance was observed following silencing of SA-upregulated ribosomal protein gene L18 (GaRPL18), while Tang et al (2019) found that silencing of three Wall Are Thin genes resulted in increased SA levels and lignin synthesis and, subsequently, enhanced resistance to V. dahliae. Our results indicate a beneficial effect of SAR response in one of the olive-ND V. dahliae isolates used.…”

The atypical E2F transcription factor DEL1 modulates growth–defense tradeoffs of host plants during root-knot nematode infection

“…In addition, transgenic and mutant plants with elevated basal SA levels also exhibit growth reduction 13,[22][23][24] . Moreover, recent studies have shown that SA accumulation in response to pathogen attack positively correlates with lignin deposition and acquisition of immunity [30][31][32][33] . In light of these lines of evidence, DEL1 may mediate the balance between defense and growth by limiting SA accumulation during RKN infection in root.…”

Genome-Wide Analysis of OPR Family Genes in Cotton Identified a Role for GhOPR9 in Verticillium dahliae Resistance

“…The technology of virus-induced gene silencing was performed as reported previously [ 42 ]. Fragments of GhOPR9 and GhPDS for evaluating VIGS marker gene were amplified from G. hirsutum cv.…”