The early transcriptome response of cassava (Manihot esculenta Crantz) to mealybug (Phenacoccus manihoti) feeding
2018
The
mealybug,
Phenacoccus manihoti, is a leading pest of cassava (
Manihotesculenta Crantz), damaging this crop globally. Although the biological control of this
mealybugusing natural predators has been established, resistance breeding remains an important means of control. Understanding plant responses to insect herbivory, by determining and identifying differentially expressed genes (DEGs), is a vital step towards the understanding of molecular mechanisms of defence responses in plants and the development of resistant cultivars by gene editing. Morphological and molecular analysis confirmed the
mealybugidentity as
Phenacoccus manihoti(Matile-Ferrero). The transcriptome response of the green mite resistant cassava genotype AR23.1 was compared to P40/1 with no known resistance at 24 and 72 hours of
mealybug
infestationcompared to non-
infestedmock. A total of 301 and 206 genes were differentially expressed at 24 and 72 of
mealybug
infestationfor AR23.1 and P40/1 genotypes respectively, using a log2
fold changeand P-value ≤ 0.05. Gene ontology functional classification revealed an enrichment of genes in the
secondary metabolicprocess category in AR23.1 in comparison with P40/1, while genes in the regulation of molecular function, cellular component biogenesis and electron carrier categories were more significantly enriched in P40/1 than in AR23.1.
Biological pathwayanalysis, based on
KEGG, revealed a significant enrichment of plant-pathogen interaction and
plant hormonalsignal transduction pathways for a cohort of up-regulated and down-regulated DEGs in both genotypes. Defence-related genes such as 2-oxogluterate,
gibberellinoxidase and terpene synthase proteins were only induced in genotype AR23.1 and not in P40/1, and subsequently validated by RT-qPCR. The study revealed a difference in response to
mealybug
infestationin the two genotypes studied, with AR23.1 showing a higher number of differentially expressed transcripts post
mealybug
infestationat 24 and 72 hours. Candidate defence-related genes that were overexpressed in the AR23.1 genotype post
mealybug
infestationwill be useful in future functional studies towards the control of
mealybugs.
Keywords:
-
Correction
-
Source
-
Cite
-
Save
113
References
9
Citations
NaN
KQI