Maize growth and developmental responses to temperature and ultraviolet-B radiation interaction

Abstract

Plant response to the combination of two or more abiotic stresses is different than its response to the same stresses singly. The response of maize (Zea mays L.) photosynthesis, growth, and development processes were examined under sunlit plant growth chambers at three levels of each day/night temperatures (24/16°C, 30/22°C, and 36/28°C) and UV-B radiation levels (0, 5, and 10 kJ m -2 d -1 ) and their interaction from 4 d after emergence to 43 d. An increase in plant height, leaf area, node number, and dry mass was observed as temperature increased. However, UV-B radiation negatively affected these processes by reducing the rates of stem elongation, leaf area expansion, and biomass accumulation. UV-B radiation affected leaf photosynthesis mostly at early stage of growth and tended to be temperature-dependent. For instance, UV-B radiation caused 3-15% decrease of photosynthetic rate (P N ) on the uppermost, fully expanded leaves at 24/16°C and 36/28°C, but stimulated P N about 5-18% at 30/22°C temperature. Moreover, the observed UV-B protection mechanisms, such as accumulation of phenolics and waxes, exhibited a significant interaction among the treatments where these compounds were relatively less responsive (phenolics) or more responsive (waxes) to UV-B radiation at higher temperature treatments or vice versa. Plants exposed to UV-B radiation produced more leaf waxes except at 24/16°C treatment. The detrimental effect of UV-B radiation was greater on plant growth compared to the photosynthetic processes. Results suggest that maize growth and development, especially stem elongation, is highly sensitive to current and projected UV-B radiation levels, and temperature plays an important role in the magnitude and direction of the UV-B mediated responses.

Increasing temperature within thermal limits compensates negative ultraviolet‐B radiation effects in terrestrial and aquatic organisms

“…For a number of studies, organisms were grown at the ambient temperature over several months or years, during which time the temperature fluctuated and the treatment represented an increase by a given number of degrees C above the ambient temperature (Supporting Information Table S1). For instance, in the study of Singh, Reddy, Reddy, and Gao (), the temperature level 24/16 °C (day/night) was taken as the control, and the temperature levels 30/22 °C and 36/28 °C were considered individually as treatments (Supporting Information Table S1). Ideally, the optimum temperature should be considered as the control.…”

Ultraviolet (UV) B effects on growth and yield of three contrasting sweet potato cultivars

“…showed reduction in plant height (by 7%), leaf area (by 15%), and photosynthetic rate (by 26%) with the same UV-B treatments (Koti et al 2007). Additionally, UV-B increased chemical composition of UV-absorbing compounds and pigments in maize leaves by 51% at 10 kJ m -2 d -1 UV-B (24/16°C) (Singh et al 2014).…”

“…Approximately 20% of crops are sensitive to UV-B radiation regarding dry mass reduction (Teramura 1983). Previous studies had already covered soybean (Koti et al 2007), cotton (Kakani et al 2003), and maize (Singh et al 2014, Wijewardana et al 2016. For example, it was found that 10 kJ m -2 d -1 UV-B (the projected UV-B level) had multiple negative effects on maize (Zea mays L.) including reduced plant height (by 36%), leaf area (by 22%), and photosynthetic rate (by 5-15%) compared to 0 kJ m -2 d -1 treatment (Singh et al 2014).…”

The effect of foliar spray fertilizers on the tolerance of Hordeum vulgare to UV-B radiation and drought stress

“…Cereal Research Communications 45, 2017 The effect of drought stress and UV-B radiation on crop plants varies depending on the intensity of stress and the crop growth stage (Singh et al 2014). The effect of UV-B on plants depends on radiation rates and wavelength, and has a cumulative character; the longer the time of exposure, the greater the effect of its action (Bandurska et al 2013).…”

“…Some of the deleterious effects of UV-B radiation on plants include DNA damage, dilation and disintegration of cellular membranes, photooxidation of leaf pigments and phytohormones, and inhibition of photosynthesis (Reddy et al 2013). The UV-B protective mechanism in plants involves photoreactivation to repair DNA damage, accumulation of UV-B absorbing compounds (e.g., phenolic compounds) and waxes in the leaf epidermis to partially block UV-B radiation (Singh et al 2014). Therefore, the plant responses are not stress responses but are rather associated with UV-B protection or amelioration of damage (Bandurska et al 2013).…”