Constitutive expression of a novel antimicrobial protein, Hcm1, confers resistance to both Verticillium and Fusarium wilts in cotton

Abstract

Fusarium and Verticillium wilts, two of the most important diseases in cotton, pose serious threats to cotton production. Here we introduced a novel antimicrobial protein Hcm1, which comprised harpin protein from Xanthomonas oryzae pv. oryzicola (Xoc), and the chimeric protein, cecropin A-melittin, into cotton. The transgenic cotton lines with stable Hcm1 expression showed a higher resistance to Verticillium and Fusarium wilts both in greenhouse and field trials compared to controls. Hcm1 enabled the transgenic cotton to produced a microscopic hypersensitive response (micro-HR), reactive oxygen species (ROS) burst, and caused the activation of pathogenesis-related (PR) genes in response to biotic stress, indicating that the transgenic cotton was in a primed state and ready to protect the host from pathogenic infection. Simultaneously, Hcm1 protein inhibited the growth of Verticillium dahliae (V. dahliae) and Fusarium oxysporum (F. oxysporum) in vitro. The spread of fungal biomass was also inhibited in vivo since the V. dahliae biomass was decreased dramatically in transgenic cotton plants after inoculation with V. dahliae. Together, these results demonstrate that Hcm1 could activate innate immunity and inhibit the growth of V. dahliae and F. oxysporum to protect cotton against Verticillium and Fusarium wilts.

Functional regions of HpaXm as elicitors with specific heat tolerance induce the hypersensitive response or plant growth promotion in nonhost plants

“…Hydrogen peroxide (H 2 O 2 ) is an important signal molecule in the pathway [ 11 , 16 , 17 ], and its accumulation in plant tissues can be detected using 3, 3’-diaminobenzidine (DAB) dyes [ 18 , 19 ]. The three youngest fully expanded tobacco leaves were evenly sprayed with a 1 μM solution of the unheated or heated protein/synthetic peptide treatments and then harvested 0, 1, 3, 6, 9, 12, 24 and 72 hours post spraying.…”

5-Aminolevulinic Acid Dehydratase Gene Dosage Affects Programmed Cell Death and Immunity

“…To quantify the fungal biomass in cotton leaves, the first true leaves of the cotton plants inoculated with V991 were collected for DNA extraction. The amounts of fungal DNA were quantified by calculating the products of the ITS1 and ITS2 regions of the rRNA genes (Z29511) of V. dahliae relative to the products of cotton histone gene (AF024716; Zhang et al, 2016). Fungal accumulation was also demonstrated by microscopy based on the intensity of the brown stem discoloration resulting from the fungi accumulation.…”

Transcriptomic analysis of gene expression of Verticillium dahliae upon treatment of the cotton root exudates

“…To combat the challenge of V. dahliae, resistance cotton has evolved multiple layers of defense mechanisms, including tissue composition, physiological and biochemical resistance, during the long time period of coexistence and arm race [6][7][8][9][10]. In recent years, with the application of genomics, transcriptomics and proteomics, great progress has been made in understanding the molecular mechanism underlying cotton's resistance against V. dahliae, and a number of genes related to V. dahliae resistance have been identified [11][12][13][14][15][16]. On the other hand, in view of the co-evolving relationship between cotton and V. dahliae, it is also of vital importance to study the molecular mechanisms determining the pathogenicity of V. dahliae.…”