A transgenic approach to investigate the role of a mannose binding lectin gene on strawberry (Fragaria ×ananassa) resistance to fungal pathogens

White strawberry fruits (Fragaria ×ananassa) are more resistant to anthracnose disease caused by Colletotrichum spp. compared with red fruits.
In white fruit infected with C. acutatum, a mannose binding lectin gene named FaMBL1 was found to be the most upregulated gene.
In order to discern its role in strawberry resistance to C. acutatum, FaMBL1 silencing and overexpressing strawberry plants were generated through Agrobacterium tumefaciens transformation technique.
Transformed strawberry lines were screened by selective media and specific amplicons via PCR. Copy number of target genes in the selected lines was determined by droplet digital PCR. Four overexpressing and three silencing lines, albeit with various copy number, were obtained.
RT-PCR assay was conducted on different overexpressing lines, using RNA extracted from young leaves.
The relative expressions of FaMBL1, some hormone-related-defence genes (FaAOS1, FaPAD4, FaEDS1, FaNCED1, FaZEP) and other defence-related genes (FaGSL5, FaPR1.2, FaWRKY1, FaPAL1) were quantified.
The expression level of FaMBL1 gene in overexpression lines was significantly higher than wild type, while the difference for the defence-related genes was not that obvious.
Interestingly, copy number of lectin transgene did not correlate with the level of expression of lectin gene in overexpressing lines.

IX International Strawberry Symposium

L. Ma, D. Gebremichael, Z. Mehari, F. Negrini, S. Sabbadini, B. Mezzetti, E. Baraldi

Colletotrichum acutatum, stable transfection, silencing, overexpressing, copy number

https://doi.org/10.17660/ActaHortic.2021.1309.1