A sugarcane cystatin: recombinant expression, purification, and antifungal activity

Area of Science:

• Plant pathology
• Biochemistry
• Molecular biology

Background:

• Sugarcane is vulnerable to fungal diseases, leading to significant production losses.
• Protease inhibitor proteins, like cystatins, are natural plant defenses against pathogens.
• Cystatins specifically inhibit cysteine proteases, crucial for pathogen survival and growth.

Purpose of the Study:

• To investigate the potential of sugarcane cystatins as a biocontrol agent against phytopathogens.
• To express and purify a specific sugarcane cystatin in Escherichia coli.
• To characterize the antifungal activity and structural integrity of the purified sugarcane cystatin.

Main Methods:

• Expression of sugarcane cystatin in Escherichia coli.
• Purification of the recombinant sugarcane cystatin protein.
• Antifungal activity assays against the filamentous fungus Trichoderma reesei.
• Circular dichroism spectroscopy to assess protein folding and secondary structure.

Main Results:

• The sugarcane cystatin was successfully expressed and purified.
• Circular dichroism analysis indicated a secondary structure similar to oryzacystatin I.
• The purified cystatin exhibited significant inhibitory activity against the growth of Trichoderma reesei.

Conclusions:

• Sugarcane cystatins possess inherent antifungal properties.
• The characterized sugarcane cystatin shows promise as a novel agent for controlling pathogenic fungi in sugarcane.
• This research supports the development of sustainable, plant-derived strategies for crop protection.