Sugarwin: a sugarcane insect-induced gene with antipathogenic activity

Area of Science:

• Plant Biology
• Biochemistry
• Entomology

Background:

• Sugarcane is susceptible to fungal infections after insect damage, primarily from the caterpillar Diatraea saccharalis.
• Plants possess defense mechanisms involving wound-inducible proteins to combat pests and pathogens.

Purpose of the Study:

• To investigate the role of sugarcane wound-inducible proteins (SUGARWINs) in plant defense against insect damage and subsequent fungal invasion.
• To characterize the expression patterns and functional properties of SUGARWIN proteins.

Main Methods:

• In silico analysis to identify BARWIN homologues (SUGARWINs).
• Generation of a SUGARWIN::green fluorescent protein fusion to track protein localization.
• Analysis of sugarwin transcript induction via mechanical wounding, insect damage, and methyl jasmonate treatment.
• Assessment of SUGARWIN protein's effect on insect development and fungal morphology.

Main Results:

• SUGARWIN::GFP fusion protein localized to the endoplasmic reticulum and extracellular space.
• Sugarwin transcript levels increased in response to wounding, D. saccharalis damage, and methyl jasmonate, with late induction restricted to the wound site.
• SUGARWIN protein did not affect insect development but induced apoptosis in fungal germlings, altering their morphology.

Conclusions:

• Sugarcane evolved sugarwin genes for their antipathogenic activity, enhancing defense against fungal invasion post-insect damage.
• Induction of sugarwin gene expression serves as a coordinated plant defense strategy against opportunistic fungi following D. saccharalis feeding.