A small heat shock protein gene ( RcHSP17.8 ) from Chinese rose confers resistance to various abiotic stresses in transgenic tobacco

RcHSP17.8 isolated from Chinese rose is an induced cytoplasmic class I small heat shock protein, first reported in Chinese rose. To study its physiological function, we inserted the open reading frame of RcHSP17.8 into tobacco and positive transgenic plants were obtained. The transgenic tobacco plants were treated with various stress conditions such as high temperature, drought, osmotic stress, and high salt, and their morphology, water loss rate, electrical conductivity, proline content, and expression patterns of endogenous and exogenous genes were investigated. The results of these physio-biochemical and molecular biological analyses showed that the transgenic tobacco plants exhibited a remarkable resistance phenotype compared with the control (empty vector-transformed tobacco plants). The electrical conductivity was lower in the transgenic tobacco plants compared with the control, while the proline content was substantially increased. Additionally, the transgenic tobacco plants had a reduced water loss rate and higher expression of the endogenous P5CS gene compared with the controls. These results indicated that the RcHSP17.8-transformed tobacco seedlings exhibited remarkable resistance to high temperature and osmotic stresses compared with the control group. This study provides a theoretical basis for genetic engineering research for quality improvement of Chinese rose and other ornamental flowers. RcHSP17.8 was high-expressed in heat-tolerant but not in non-heat-tolerant varieties after heat shock. The tolerance of recombinant strains and transgenic tobacco to abiotic stresses was enhanced.