Constitutive expression of ABR17 cDNA enhances germination and promotes early flowering in Brassica napus

Pathogenesis-related 10 (PR 10) proteins are induced in a number of angiosperms and gymnosperms following exposure to abiotic or biotic stresses, but their biological function remains unknown. However, the constitutive expression of a PR 10 cDNA has been reported to enhance germination and abiotic stress tolerance in Arabidopsis thaliana. In the present study, we report the constitutive expression of Pisum sativum ABA-responsive 17 (ABR17/PR 10.4) cDNA in an important agricultural species, Brassica napus (canola,) to determine its effects on germination as well as other characteristics. We observed significantly greater germination in the transgenic line at 275 mM NaCl, 5 °C, and 10 °C + 75 mM NaCl when compared to the wild type. In addition, we observed a significantly greater rate of flowering, significantly earlier flowering and greater height in the transgenic line when compared to the wild type at 42 days after planting. Proteome analysis of our transgenic line revealed surprisingly few transgene-induced changes but identified carbonic anhydrase, which may be potentially responsible for some of the observed characteristics, as being elevated. Our study demonstrates that ABR17 promotes germination and early flowering in canola and possible applications are discussed.