Physiological and molecular features predispose native and invasive populations of sweet briar (Rosa rubiginosa L.) to colonization and restoration of drought degraded environments

The aim of this study was to determine physiological and molecular grounds for high adaptation potential of invasive populations of Rosa rubiginosa to soil drought. We assume that the invasive populations possess specific and effective adaptive mechanisms making them capable pioneer and nurse plants in dry environments. By colonizing the land, they limit its degradation and initiate revitalization of areas damaged by soil droughts. We analyzed plant water status, the photosynthetic apparatus activity, carbohydrate and phenolic content, the level of non-enzymatic antioxidants and RbcL protein associated with fixation of CO₂. The research involved native (Northern Hemisphere: Poland, Spain) and invasive (Southern Hemisphere: Argentine, New Zealand) populations. Contrary to the native population, the invasive one demonstrated soil drought induced specific responses aimed at maintaining high water potential in the leaves, greater content of soluble carbohydrates, and higher osmotic potential. In the invasive population, the accumulation of soluble carbohydrates prevailed over their consumption for the synthesis of phenolic compounds. The invasive plants also maintained high content of assimilation pigments and showed greater level of non-enzymatic antioxidants. Reduced activity of the photosynthetic apparatus was associated both with increased energy amount dissipated from PSII and the efficiency with which an electron can move from the reduced intersystem electron acceptors to the PSI end electron acceptors. The study results pave the path for further research on the genetic basis of sweet briar response to soil drought in the context of progressive steppe formation and desertification.