A Novel Biomarker Test for Sugarcane Yellow Canopy Syndrome ^†

Abstract

Yellow canopy syndrome (YCS) is a condition that affects sugarcane crops throughout Queensland, and is most apparent in the warmer summer months when plants are actively growing. Key symptoms of YCS include a yellowing of the mid-canopy leaves, and the accumulation of sucrose and α-glucans in the lamina, midrib and sheath tissue. As no cause for the syndrome has yet been found, a biomarker test for identifying YCS, as distinct from other conditions that cause leaf yellowing, is important to enable early detection before any signs of visual yellowing. This will inform YCS management practices, and drive the research forward. We used an RNAseq and bioinformatic approach to identify six YCS-specific biomarker candidate plant transcripts that were uniquely and consistently up-regulated in YCS. We designed primers against these transcripts, and developed a novel reverse-transcriptase polymerase chain reaction (RT-PCR) test to identify sugarcane plants affected by YCS. The YCS biomarker test is showing early signs of success and is undergoing further validation, with the aim of correctly identifying YCS-affected sugarcane plants before symptoms become apparent. This poster outlines the biomarker candidate discovery and test development process.