The mannose‐binding lectin gene FaMBL1 is involved in the resistance of unripe strawberry fruits to Colletotrichum acutatum

Abstract

The fungal pathogen Colletotrichum acutatum is the causal agent of strawberry (Fragaria × ananassa) anthracnose. Although the fungus can infect strawberry fruits at both unripe and ripe stages, the symptoms appear only on red ripe fruits. On white unripe fruits, the pathogen becomes quiescent as melanized appressoria after 24 h of interaction. Previous transcriptome analysis has indicated that a mannose-binding lectin (MBL) gene is the most up-regulated gene in 24-h-infected white strawberries, suggesting a role for this gene in the low susceptibility of unripe stages. A time course analysis of the expression of this MBL gene, named FaMBL1 (Fragaria × ananassa MBL 1a), was undertaken to monitor its expression profile in white and red fruits at early interaction times: FaMBL1 was expressed exclusively in white fruit after 24 h, when the pathogen was quiescent. Agrobacterium-mediated transient transformation was used to silence and overexpress the FaMBL1 gene in 24-h-infected white and red strawberries, respectively. FaMBL1-silenced unripe fruits showed an increase in susceptibility to C. acutatum. These 24-h-infected tissues contained subcuticular hyphae, indicating pathogen penetration and active growth. In contrast, overexpression of FaMBL1 in ripe fruits decreased susceptibility; here, 24-h-infected tissues showed a high percentage of ungerminated appressoria, suggesting that the growth of the pathogen had slowed. These data suggest that FaMBL1 plays a crucial role in the resistance of unripe strawberry fruits to C. acutatum.

Fusarium oxysporum Triggers Tissue-Specific Transcriptional Reprogramming in Arabidopsis thaliana

“…Ginkbilobin-2, a secreted MBL from Ginkgo biloba , inhibits the growth of F . oxysporum [ 42 ] and several other MBLs exhibit antifungal activity [ 43 – 46 ].…”

Unfoldome variation upon plant-pathogen interactions: strawberry infection by Colletotrichum acutatum

“…In addition, the tight link between the maturation stage and the success of fungal propagation was the reason to screen both the unripe and ripe fruits. This analysis showed several defense related genes, such as the one encoding a lectin protein, which was experimentally proved to be determinant for the low susceptibility of white fruits (Guidarelli et al 2014).…”

“…The study reported the difference in gene expression in white unripe and red ripe strawberry fruits, both in the absence and in the presence of pathogen inoculation. These genes are possibly correlated with the different susceptibility of fruit ripening stages, as recently demonstrated for one gene encoding a lectin protein (Guidarelli et al 2014). …”

Dual Transcriptome and Metabolic Analysis of Vitis vinifera cv. Pinot Noir Berry and Botrytis cinerea During Quiescence and Egressed Infection

“…From the transcriptional alteration of RLKs, lectin protein kinase and protein kinase 1 seem to be quiescentstage-specific. The putative orthologues in other species are associated to plant immunity (Guidarelli et al, 2014), in particular the latter is known to mediate signaling in response to B. cinerea (Abuqamar et al, 2008). In addition, transcripts related to Ca 2+ mediated signaling (such as calcium-and calmodulin-binding proteins) and oxidative stresses (mainly GST and cytochrome P450 monooxygenases) were also found to be possibly involved in the ongoing berry immunity.…”