Overexpression of miR408 influences the cotton response to boron toxicity

Ibrahim Ertan Erkan1* and Ufuk Celikkol Akcay1
Boron toxicity is a severe abiotic stress affecting plant growth and productivity in semi-arid regions of the world including Anatolian plateau. In this study, we investigated antioxidative responses of cotton (Gossypium hirsutum L.) as well as four different B transporter and aquaporin gene activities, which are early B stress responders, by using miR408 overexpression strategy. miR408 is a conserved microRNA in plant kingdom involved in almost all physiological responses of the plants as well as responses under abiotic and biotic stresses. Our results showed that, miR408 overexpression improved overall antioxidative status of cotton plants under B stress, in terms of reduced ion leakage and malondialdehyde levels and increased proline, chlorophyll and relative water contents. We also detected strong B transporter BOR1, BOR2 and water channel PIP1;1 and PIP2;1 gene expression in cotton leaf tissues under almost all treatments. miR408 overexpressing plants exhibited differential gene expression patterns when compared to control plants, always increasing with stress duration, revealing direct or indirect regulation of the genes by miR408 under B toxicity. Our results showed that, miR408 overexpression can be used as a strategy to improve B toxicity tolerance of cotton plants to increase agricultural production or for phytoremediation purposes on B rich soils.
Keywords: Boron toxicity, Gossypium hirsutum, miR408, overexpression.
1Isparta University of Applied Sciences, Faculty of Agriculture, Department of Agricultural Biotechnology, Isparta, Turkey.
*Corresponding author (ibrahimertanerkan@gmail.com).