Transcriptomic Profiling of Sugarcane White Leaf (SCWL) Canes during Maturation Phase

Area of Science:

• Plant Pathology
• Molecular Biology
• Agricultural Science

Background:

• Sugarcane white leaf (SCWL) disease, caused by *Candidatus* Phytoplasma sacchari, significantly damages sugarcane plantations and reduces sugar yield.
• Infected canes may appear asymptomatic, leading to accidental use as seed canes and further spread of the disease.

Purpose of the Study:

• To investigate the transcriptomic profiles of SCWL-infected and asymptomatic sugarcane at the harvesting stage.
• To elucidate the molecular mechanisms underlying SCWL disease development and its impact on sugarcane physiology.

Main Methods:

• Comparative transcriptomic analysis of SCWL-infected and asymptomatic 12-month-old sugarcane canes.
• Analysis of gene expression patterns related to photosynthesis, metabolism, defense mechanisms, and hormone signaling.

Main Results:

• SCWL infection suppressed photosynthesis and chlorophyll metabolism, reduced sugar content by blocking sucrose transport, and altered plant defense pathways.
• Upregulation of defense-related genes (MAPK, hormone signaling, phenylpropanoid pathway) and downregulation of CPK and flavonoid biosynthesis were observed.
• Phytoplasma colonization led to lignin and calcium accumulation, while sesquiterpene biosynthesis may attract insect vectors.

Conclusions:

• The study provides the first comprehensive sugarcane-phytoplasma interaction profile during harvesting.
• Understanding these molecular mechanisms is crucial for developing sustainable management strategies to prevent SCWL disease and protect the sugar industry.