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.

Special issue in honour of Prof. Reto J. Strasser - Sporulation modifies the photosynthetic activity of sporotrophophyll leaves of Platycerium bifurcatum

“…This should be explained by the susceptibility of PItotal to changes in the antenna properties manifested in the efficiency of electron trapping and their transport outside of QA (Kalaji et al 2014). Until now, this process has been observed in P. bifurcatum and other species under environmental stress (Živčák et al 2008, Miszalski et al 2016, Oliwa and Skoczowski 2019a.…”

“…In turn, nest leaves perform mainly mechanical functions, since they fasten the plant onto the tree and accumulate water and mineral substances. Thus, the two types of leaves serve different physiological functions and undergo different types of metabolism (Oliwa et al 2016(Oliwa et al , 2017Oliwa and Skoczowski 2019a).…”

“…Motivated by growing anthropopressure in tropical forests, ecophysiological studies -some of which used the Chl a fluorescence analysis -have been conducted in recent years. They mainly concerned P. bifurcatumꞌs response to drought stress, light stress, and high ozone concentration (Rut et al 2003, Sanusi et al 2011, Oliwa and Skoczowski 2019a and its ontogenetic development in different light conditions (Oliwa et al 2016(Oliwa et al , 2017. However, according to the authorsꞌ knowledge, the scientific literature lacks information on energy distribution and assimilation activity of leaves during the sporulation process not only in P. bifurcatum, but in ferns in general.…”

Ecophysiological Variability of Alnus viridis (Chaix) DC. Green Alder Leaves in the Bieszczady Mountains (Poland)

“…R is the intensity of reflectance at the wavelength (in nm) given in the index. The reflectance difference and sensitivity allow for the identification of wavelength, at which the reflectance value changes most, under the influence of environmental stress [58]. The reflectance difference (RD) was calculated according to the formula given by Carter et al [47]:…”

Response of the photosynthetic apparatus in the tropical fern Platycerium bifurcatum to increased ozone concentration

“…Due to the decorative nature of the plant, previous studies on P. bifurcatum have concerned mainly micropropagation. In recent years, ecophysiological issues related to the tolerance of P. bifurcatum to environmental stress, including light stress and drought stress, have been taken up (Rut et al 2003, Oliwa andSkoczowski 2019).…”