improves abiotic stress resistance in chrysanthemum.

RESPONSIVE TO DESSICATION 20 (RD20) is a member of the caleosin family, which is involved in plant growth and development, signal transduction, abiotic stress and plant immunity. However, the molecular mechanism of the biological function of RD20 in turnip is still largely unknown. This study aimed to characterise the roles of BrRD20 during abiotic stress resistance and their responses in various abiotic stresses by isolating BrRD20 (MK896873) from 'Tsuda' turnip. Quantitative polymerase chain reaction analysis showed that the highest expression levels of BrRD20 occurred in the petal, followed by the leaf, bud and red root epidermis, with tissue specificity. The transcript level of BrRD20 was much higher under natural light than under dark conditions in 0-5-day-old turnip seedlings. BrRD20 was also induced to be regulated by abiotic stresses such as high or low temperature, dehydration, osmotic hormone salt and alkali stresses. BrRD20 overexpression (BrRD20 -OE) in Chrysanthemum presented an enhanced tolerance to low temperature, dehydration and salt stress compared with the wild type. The BrRD20 gene was induced to be regulated by abiotic stresses such as high or low temperature, dehydration, osmotic and salt stresses. The BrRD20 gene also improved abiotic stress resistance in chrysanthemum. The above results suggested that BrRD20 plays a crucial role in abiotic stress resistance.