Improving sugarcane’s resilience to salinity and drought

Crops like sugarcane, rice, wheat and maize rely on irrigation. As they’re so thirsty, they are also susceptible to drought. Finding a way to protect the crops from drought is a challenge that needs a solution as soon as possible.

One option for improving a plant’s ability to cope with water limitation is through transgenic approaches. Scientists are finding more and more genes that plants use to cope with water scarcity. A goodly number of genes that respond to drought encode proteins with unknown functions.

Begcy et al. characterized a gene in response to environmental stresses. This has allowed them to gain insight into the unknown fraction of the sugarcane genome. Scdr2 (Sugarcane drought-responsive 2) encodes a small protein. The gene shares highly conserved sequences within monocots, dicots, algae and fungi. The authors examined plants overexpressing the Scdr2 sugarcane gene for their response to salinity and drought.

Experiment results
Effect of drought and salinity in tobacco seedlings overexpressing Scdr2. Image Begcy et al. 2019.

Overexpression of Scdr2 enhanced germination rates in tobacco seeds under drought and salinity conditions. Juvenile transgenic plants overexpressing Scdr2 and subjected to drought and salinity stresses showed: higher photosynthesis levels, internal CO2 concentration and stomatal conductance, reduced accumulation of hydrogen peroxide in the leaves, no penalty for photosystem II and faster recovery after submission to both stress conditions. Respiration was not strongly affected by both stresses in the Scdr2 transgenic plants, whereas wild-type plants exhibited increased respiration rates.

The authors conclude that Scdr2 is involved in the response mechanism to abiotic stresses. Higher levels of Scdr2 enhanced resilience to salinity and drought, and this protection correlated with reduced oxidative damage. Scdr2 confers, at the physiological level, advantages to climate limitations. Therefore, Scdr2 is a potential target for improving sugarcane resilience to abiotic stress.