The competition between winter rape (C3) and maize (C4) plants in response to elevated carbon dioxide and temperature, and drought stress

Abstract

The aim of this study was to estimate the effects of drought stress under elevated CO 2 and temperature on the competition between winter rape and maize plants. The experiment was conducted in a controlled-environment growth chamber at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry. Plants grown in monoculture (100:0) or in mixture (winter rape:maize, 50:50) irrigated and non-irrigated (drought stress), were exposed to ambient environment conditions -day/night temperature 21/14°C, CO 2 -350 ppm (CO 2 T), and enhanced environment conditions -day/night temperature 30/23°C, CO 2 -700 ppm (+CO 2 T). Maize (C 4 ) grown in mixture with winter rape (C 3 ), had significantly smaller assimilating leaf area and produced less fresh mass at CO 2 T and +CO 2 T, as compared to monoculture, and water deficit strengthened the negative effect. Comparison of the data obtained for monoculture revealed that elevated CO 2 and temperature in the conditions of sufficient moisture supply had significantly positive effect on maize assimilating leaf area (increased ~21%) and fresh mass accumulation (increased ~22%). Assimilating leaf area and fresh mass of winter rape and maize monocultures significantly decreased in response to water deficit both at CO 2 T and +CO 2 T. Water shortage had a stimulating effect on chlorophylls in leaves of winter rape in monocultures and mixtures. At +CO 2 T and sufficient water supply, maize in monoculture and mixture with rape significantly reduced the content of chlorophyll a. Carotenoid content significantly decreased in maize leaves (monoculture and mixture) under +CO 2 T in both irrigated or non-irigated substrates. Winter rape, in monoculture and mixture, accumulated significantly higher content of carotenoids under water deficit and ambient CO 2 T. However, a significant decrease in carotenoids was determined in rape leaves under +CO 2 T. The elevated contents of ascorbic acid, total phenolics and antioxidant potential indicate high capacity of winter rape to counter oxidative stress.

Plant Responses to Global Climate Change and Urbanization: Implications for Sustainable Urban Landscapes

“…Urban aspects: These trees are recognized as eco-sustainable tools for monitoring and reducing air pollution [77]. Besides trees, urban herbaceous species also play a significant Physiological aspects: Elevated carbon dioxide levels can lead to higher levels of phenols and ascorbic acid, which are instrumental in mitigating the impact of reactive oxygen species (ROS) [67,75]. Additionally, increased carbon dioxide levels influence arbuscular and ectomycorrhizal fungi, enhancing nutrient and water supply to plants and facilitating the functioning of plant-growth-promoting bacteria (PGPB) [76].…”

The effect of a growth regulator Ribav-Extra on winter wheat seedlings exposed to heavy metals

“…Modern agriculture seeks to achieve the maximum productivity of agricultural plants and to obtain a yield that does not contain substances toxic to humans and animals (Lazauskas et al, 2012). Bioactive compounds are extensively reported to confer tolerance to environmental stresses in plants (Asgher et al, 2015;Miliauskienė et al, 2016). Thus, exogenous application of plant growth regulators (PGRs) can significantly Nano titanium dioxide and nitric oxide alleviate salt induced changes in seedling growth, physiological and photosynthesis attributes of barley modulate both enzymatic and non-enzymatic components of the antioxidant defence system, neutralize the negative impact of heavy metals such as alterations in the activity of enzymes of radical scavenging system, and are capable of improving plant growth or/and biomass accumulation, chlorophyll and carotenoid content, the rate of photosynthesis, heavy metals accumulation in yield, etc.…”