A small-scale spatial heterogeneity in photochemical reflectance index and intensity of reflected light at 530 nm in pea (Pisum sativum) leaves is sensitive to action of salinization.

Remote sensing of stressor action on plants is an important step of their protection. Measurement of photochemical reflectance index (PRI) can be used to detect action of stressors including salinization; potentially, a small-scale spatial heterogeneity of PRI (within leaf or its part) can be an indicator of this action. The current work was devoted to analysis of sensitivity of the small-scale heterogeneity in PRI and in the reflected light intensity at 530nm (approximately corresponding to the measuring wavelength for PRI) in leaves of pea (Pisum sativum ) plants to action of salinization. Plants were cultivated under controlled conditions of a vegetation room and under open-air conditions. It was shown that both the standard deviation of PRI and coefficient of variation of the reflected light intensity at 530nm were sensitive to action of salinization on plants. Moreover, this variation coefficient was negatively corelated to the potential quantum yield of PSII; i.e. increasing the coefficient could be used to estimate decreasing this yield caused by photodamage of PSII under salinization. Our results show that the small-scale spatial heterogeneity in PRI and the reflected light intensity at 530nm can be used as additional tools of the remote sensing of plant responses under action of salinization.