Overexpression ofNictaba-Like Lectin Genes fromGlycine maxConfers Tolerance towardPseudomonas syringaeInfection, Aphid Infestation and Salt Stress in TransgenicArabidopsisPlants.
Plants have evolved a sophisticated immune system that allows them to recognize invading pathogens by specialized receptors. Carbohydrate-binding proteins or lectins are part of this immune system and especially the lectins that reside in the nucleocytoplasmic compartment are known to be implicated in biotic and abiotic stress responses. The class of Nictaba-like lectins (NLL) groups all proteins with homology to the tobacco (Nicotiana tabacum) lectin, known as a stress-inducible lectin. Here we focus on two Nictaba homologs from soybean (Glycine max), referred to asGmNLL1 andGmNLL2. Confocal laser scanning microscopy of fusion constructs with the green fluorescent protein either transiently expressed inNicotiana benthamianaleaves or stably transformed in tobacco BY-2 suspension cells revealed a nucleocytoplasmic localization for theGmNLLs under study. RT-qPCR analysis of the transcript levels for the Nictaba-like lectins in soybean demonstrated that the genes are expressed in several tissues throughout the development of the plant. Furthermore, it was shown that salt treatment,Phytophthora sojaeinfection andAphis glycinesinfestation trigger the expression of particularNLLgenes. Stress experiments withArabidopsislines overexpressing theNLLsfrom soybean yielded an enhanced tolerance of the plant toward bacterial infection (Pseudomonas syringae), insect infestation (Myzus persicae) and salinity. Our data showed a better performance of the transgenic lines compared to wild type plants, indicating that the NLLs from soybean are implicated in the stress response. These data can help to further elucidate the physiological importance of the Nictaba-like lectins from soybean, which can ultimately lead to the design of crop plants with a better tolerance to changing environmental conditions.
Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Ghent University Ghent, Belgium.
Sofie
S
Van Holle
Laboratory of Agrozoology, Department of Crop Protection, Ghent University Ghent, Belgium.
Guy
G
Smagghe
Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Ghent University Ghent, Belgium.
Els J M
EJ
Van Damme
Aphis glycines; Myzus persicae; Nictaba; Phytophthora sojae; Pseudomonas syringae; lectin; salt stress; soybean