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The fungal pathogen, Leptosphaeria maculans causes a severe and economically important disease to Brassica crops globally, well-known as blackleg. Besides, the anti-oxidative defense response of glucosinolates to fungal pathogens is widely established. Despite notable importance of glucosinolates in blackleg disease resistance the association of glucosinolate pathway genes in glucosinolate mediated defense response after L. maculans infection remains incompletely understood. The current study was designed to identify glucosinolate-biosynthesis specific genes among the eight selected candidates induced by L. maculans and associated alterations in glucosinolate profiles to explore their roles in blackleg resistance at the seedling stage of cabbage plants. The defense responses of four cabbage inbred lines, two resistant and two susceptible, were investigated using two L. maculans isolates, 03-02s and 00-100s. Pathogen-induced glucosinolate accumulation dynamically changed from two days after inoculation to four days after inoculation. In general, glucosinolate biosynthetic genes were induced at 24 h after inoculation and glucosinolate accumulation enhanced at two days after inoculation. An increase in either aliphatic (GIB, GRA) or indolic (GBS and MGBS) glucosinolates was associated with seedling resistance of cabbage. Pearson correlation showed the enhanced accumulation of MGBS, GBS, GIB, GIV and GRA after the inoculation of fungal isolates was associated with expression of specific genes. Principal component analysis separated two resistant cabbage lines—BN4098 and BN4303 from two susceptible cabbage lines—BN4059 and BN4072 for variable coefficients of disease scores, glucosinolate accumulation and expression levels of genes. Enhanced MGBS content against both fungal isolates, contributing to seedling resistance in two interactions—BN4098 × 03-02s and BN4303 × 00-100s and enhanced GBS content only in BN4098 × 03-02s interaction. Aliphatic GRA took part in resistance of BN4098 × 00-100s interaction whereas aliphatic GIB took part is resistance of BN4098 × 03-02s interaction. Aliphatic GIV accumulated upon BN4098 × 03-02s interaction but GSL-OH - Bol033373 and CYP81F2 - Bol026044 showed enhanced expression in BN4303 × 03-02s interaction. The association between the selected candidate genes, corresponding glucosinolates, and seedling resistance broaden the horizon of glucosinolate conciliated defense against L. maculans in cabbage seedlings. [ABSTRACT FROM AUTHOR]

Evaluation of nine exotic cabbage varieties and a local variety commenced at the Research Field of the Department of Agriculture, Noakhali Science and Technology University (NSTU), Bangladesh, following a randomized complete block design (RCBD) with three replications. This study aimed to identify the most suitable exotic varieties based on morphophysiological and biochemical traits compared with a check variety. Significant variations (P < 0.01) for all the characteristics, except chlorophyll content, emerged from the study. A highly significant positive association (r ≥ 0.75) was evident for the head diameter of cabbage varieties with head width, stump thickness, core length, and weight with folded and unfolded leaves. On cluster analysis, varieties V2, V3, and V10 were in the same clusters. About the PCA, PC1 accounted for 50.29% of the total variation. However, the maximum plant diameter (65 cm) occurred in V10, and the widest leaf petiole length (8.13 cm) was visible in V3. Yet, the highest head length (13.16 cm), head diameter (19.51 cm), head width (18.33 cm), weight with unfolded leaves (2.00 kg), and weight with folded leaves (1.44 kg) appeared in V10, which are very close to V2 and V3. Also, genetic parameters estimation and heatmap analysis revealed high genetic advance and positive variation, respectively, regarding head diameter, head width, and weight with folded and unfolded leaves. Finally, V2 and V3 varieties could better serve for further genetic improvement for cabbage growers and plant breeders in Bangladesh. [ABSTRACT FROM AUTHOR]

Cabbage (Brassica oleracea var. capitata) is an economically important crop in the family Brassicaceae. Black rot disease is a top ranked cabbage disease, which is caused by Xanthomonas campestris pv. campestris (Xcc) and may reduce 50% crop loss. Therefore, we need a clear understanding of black rot disease resistance for sustainable disease management. The secondary metabolites, like Glucosinolate (GSL) presents in Brassica species, which plays a potential role in the defense mechanism against pathogens. However, there is little known about GSL-regulated resistance mechanisms and GSL biosynthesis and the breakdown related gene expression after black rot disease infection in cabbage. In this study, relative expression of 43 biosynthetic and breakdown related GSLs were estimated in the black rot resistant and susceptible cabbage lines after Xcc inoculation. Ten different types of GSL from both aliphatic and indolic groups were identified in the contrasting cabbage lines by HPLC analysis, which included six aliphatic and four indolic compounds. In the resistant line, nine genes (MYB122-Bol026204, MYB34-Bol017062, AOP2-Bo9g006240, ST5c-Bol030757, CYP81F1-Bol017376, CYP81F2-Bol012237, CYP81F4-Bol032712, CYP81F4-Bol032714 and PEN2-Bol030092) showed consistent expression patterns. Pearson's correlation coefficient showed positive and significant association between aliphatic GSL compounds and expression values of ST5c-Bol030757 and AOP2-Bo9g006240 genes as well as between indolic GSL compounds and the expression of MYB34-Bol017062, MYB122-Bol026204, CYP81F2-Bol012237, CYP81F4-Bol032712 and CYP81F4-Bol032714 genes. This study helps in understanding the role of GSL biosynthesis and breakdown related genes for resistance against black rot pathogen in cabbage, which could be further confirmed through functional characterization either by overexpression or knock-out mutation. [ABSTRACT FROM AUTHOR]

Acidovorax citrulli (A. citrulli) strains cause bacterial fruit blotch (BFB) in cucurbit crops and affect melon significantly. Numerous strains of the bacterium have been isolated from melon hosts globally. Strains that are aggressively virulent towards melon and diagnostic markers for detecting such strains are yet to be identified. Using a cross-inoculation assay, we demonstrated that two Korean strains of A. citrulli, NIHHS15-280 and KACC18782, are highly virulent towards melon but avirulent/mildly virulent to the other cucurbit crops. The whole genomes of three A. citrulli strains isolated from melon and three from watermelon were aligned, allowing the design of three primer sets (AcM13, AcM380, and AcM797) that are specific to melon host strains, from three pathogenesis-related genes. These primers successfully detected the target strain NIHHS15-280 in polymerase chain reaction (PCR) assays from a very low concentration of bacterial gDNA. They were also effective in detecting the target strains from artificially infected leaf, fruit, and seed washing suspensions, without requiring the extraction of bacterial DNA. This is the first report of PCR-based markers that offer reliable, sensitive, and rapid detection of strains of A. citrulli causing BFB in melon. These markers may also be useful in early disease detection in the field samples, in seed health tests, and for international quarantine purposes. [ABSTRACT FROM AUTHOR]

Sclerotinia stem rot (white mold), caused by the fungus Sclerotinia sclerotiorum, is a serious disease of Brassica crops worldwide. Despite considerable progress in investigating plant defense mechanisms against this pathogen, which have revealed the involvement of glucosinolates, the host–pathogen interaction between cabbage (Brassica oleracea) and S. sclerotiorum has not been fully explored. Here, we investigated glucosinolate profiles and the expression of glucosinolate biosynthesis genes in white-mold-resistant (R) and -susceptible (S) lines of cabbage after infection with S. sclerotiorum. The simultaneous rise in the levels of the aliphatic glucosinate glucoiberverin (GIV) and the indolic glucosinate glucobrassicin (GBS) was linked to white mold resistance in cabbage. Principal component analysis showed close association between fungal treatment and cabbage GIV and GBS contents. The correlation analysis showed significant positive associations between GIV content and expression of the glucosinolate biosynthesis genes ST5b-Bol026202 and ST5c-Bol030757, and between GBS content and the expression of the glucosinolate biosynthesis genes ST5a-Bol026200 and ST5a-Bol039395. Our results revealed that S. sclerotiorum infection of cabbage induces the expression of glucosinolate biosynthesis genes, altering the content of individual glucosinolates. This relationship between the expression of glucosinolate biosynthesis genes and accumulation of the corresponding glucosinolates and resistance to white mold extends the molecular understanding of glucosinolate-negotiated defense against S. sclerotiorum in cabbage. [ABSTRACT FROM AUTHOR]

Ringspot, caused by the fungus Mycosphaerella brassicicola, is a serious disease of Brassica crops worldwide. Despite noteworthy progress to reveal the role of glucosinolates in pathogen defense, the host–pathogen interaction between cabbage (Brassica oleracea) and M. brassicicola has not been fully explored. Here, we investigated the glucosinolate profiles and expression of glucosinolate biosynthesis genes in the ringspot-resistant (R) and susceptible (S) lines of cabbage after infection with M. brassicicola. The concomitant rise of aliphatic glucoiberverin (GIV) and indolic glucobrassicin (GBS) and methoxyglucobrassicin (MGBS) was linked with ringspot resistance in cabbage. Pearson's correlation and principle component analysis showed a significant positive association between GIV contents and the expression of the glucosinolate biosynthesis gene ST5b-Bol026202 and between GBS contents and the expression of the glucosinolate biosynthesis gene MYB34-Bol017062. Our results confirmed that M. brassicicola infection induces the expression of glucosinolate biosynthesis genes in cabbage, which alters the content of individual glucosinolates. This link between the expression of glucosinolate biosynthesis genes and the accumulation of their respective glucosinolates with the resistance to ringspot extends our molecular sense of glucosinolate-negotiated defense against M. brassicicola in cabbage. [ABSTRACT FROM AUTHOR]