Different response of photosynthetic apparatus to high-light stress in sporotrophophyll and nest leaves of Platycerium bifurcatum

Abstract

Tropical forest deforestation leads to sudden changes in light conditions, which is a problem for the development of epiphytes, such as Platycerium bifurcatum. High light (HL) results in disturbances of the light phase of photosynthesis and changes in leaf pigment composition. The current study determined differences in fast chlorophyll fluorescence transients and changes in radiation reflectance in sporotrophophylls and nest leaves after one and seven days of HL. In addition, a spectral range was identified with the largest change in reflectance induced by HL. Sporotrophophylls exhibited a stronger response of the photosynthetic apparatus to photoinhibition than that of the nest leaves. Moreover, in sporotrophophylls, disorders of electron transport were visible in the whole O-P phase, and in the nest leaves mainly in the O-J phase. Higher accumulation of photoprotective compounds in sporotrophophylls underlined a different reaction to HL.