Main content area

A hybrid proline-rich cell-wall protein gene JsPRP1 from Juglans sigillata Dode confers both biotic and abiotic stresses in transgenic tobacco plants

Liu, D. Q., Han, Q., Shah, T., Chen, C. Y., Wang, Q., Tang, B. F., Ge, F.
Trees 2018 v.32 no.5 pp. 1199-1209
Allium cepa, Botryosphaeria dothidea, Escherichia coli, Fusarium solani, Fusarium verticillioides, Glomerella cingulata, Juglans sigillata, abiotic stress, antifungal properties, biotic stress, cadmium chloride, cell walls, cultivation area, drought, ethylene, genes, genetic vectors, green fluorescent protein, hybrids, hydrogen peroxide, jasmonic acid, onions, quantitative polymerase chain reaction, recombinant proteins, reverse transcriptase polymerase chain reaction, salicylic acid, tobacco, transcription (genetics), transgenic plants, walnuts
KEY MESSAGE: Walnut hybrid proline-rich protein gene JsPRP1 was induced by Colletotrichum gloeosporioides and signaling molecules. JsPRP1 protein inhibited pathogenic fungi. JsPRP1 overexpression in tobacco conferred strong resistance to abiotic and biotic stresses. Walnut (Juglans sigillata Dode) is one of the important sources of nuts and timbers in the world. With the expansion of walnut cultivation area, its disease hazards have become a serious problem. In this study, a novel hybrid proline-rich cell-wall protein gene JsPRP1 was investigated and isolated from Juglans sigillata Dode induced by Colletotrichum gloeosporioides. qRT-PCR (quantitative reverse transcription-PCR) analysis showed that JsPRP1 transcriptional level was up-regulated in J. sigillata Dode following jasmonic acid, salicylic acid, ethylene, and hydrogen peroxide treatments, and C. gloeosporioides inoculation. The JsPRP1 gene was further fused with green fluorescent protein (GFP) gene in a plant expression vector and transferred into onion (Allium cepa) epidermal cells. Laser scanning confocal microscope confirmed that JsPRP1 was expressed in the cell wall. Moreover, the JsPRP1 protein was expressed in Escherichia coli, and the recombinant protein purified by Ni–NTA column showed in vitro antifungal activity to C. gloeosporioides, Gibberella moniliformis, Botryosphaeria dothidea, and Fusarium solani. Furthermore, the plant overexpression vector of JsPRP1 was constructed and transferred into tobacco. The T₂ transgenic tobacco showed high tolerance to drought, CdCl₂, and C. gloeosporioides infection, meanwhile the accumulation of reactive oxygen species (ROS) in transgenic tobacco was significantly lower than wild-type plant under stress. The above results indicate that JsPRP1 is an important defense gene in J. sigillata Dode against drought, CdCl₂ stress, and C. gloeosporioides infection.