How does UV-B radiation affect the initial growth of common bean (Phaseolus vulgaris L.)? Physiological and structural aspects

Abstract

ABCTRACTIncreased UV-B radiation, a topic of concern due to climate change, can affect plant development through structural and physiological changes. Common bean (Phaseolus vulgaris L.) is a legume of great economic relevance, being one of the basic components of the human population's diet. Seeds of P. vulgaris var. Carioca were sown and grown in a growth chamber, and at 12 days of age were exposed for 15 min daily to UV-B radiation for a period of 14 days. Growth, leaf anatomy, gas exchange and pigments were evaluated. It was observed that UV-B radiation negatively affected the initial growth of bean plants, which had a reduction in height, number of leaves, fresh and dry leaf masses, leaf area, as well as reduction of stem and root dry masses. There was a reduction in the epidermis thickness, increase in the thickness of the palisade parenchyma and the leaf blade. It was verified yet reduction of the photosynthetic and photoprotectors pigments, reduction of the photosynthetic rate and alterations on the absorbent compounds of the UV-B radiation. The results obtained showed that the increase in UV-B radiation was harmful to the initial development of this crop.Palavras-chave: Agriculture, Anatomy, Beans, Pigments. RESUMOO aumento da radiação UV-B, tema preocupante em virtude das mudanças climáticas, pode afetar o desenvolvimento das plantas, por meio de mudanças estruturais e fisiológicas. O feijoeiro-comum (Phaseolus vulgaris L.) é uma leguminosa de grande relevância econômica, sendo um dos componentes básicos da alimentação humana. Sementes de P. vulgaris var. Carioca foram germinadas e cultivadas em uma câmara de crescimento, sendo aos 12 dias de idade expostas a 15 min diários de radiação UV-B, por um período de 14 dias. Foram avaliados crescimento, anatomia foliar, trocas gasosas e pigmentos. Observou-se que a radiação UV-B afetou negativamente o crescimento inicial do feijoeiro, o qual teve redução em altura, número de folhas, massa fresca, massa seca e área foliares, bem como, redução da massa seca de caule e raiz. Houve redução na espessura da epiderme e aumento nas espessuras do parênquima paliçádico e do limbo. Verificou-se, ainda, redução dos teores de pigmentos fotossintéticos e fotoprotetores, redução da taxa fotossintética e alterações nos compostos absorventes da radiação UV-B. Os resultados obtidos mostraram que o aumento da radiação UV-B foi prejudicial para o desenvolvimento inicial desta cultura.

Climate Stressors on Growth, Yield, and Functional Biochemistry of two Brassica Species, Kale and Mustard

“…Results observed in Arabidopsis thaliana leaves [ 64 ], soybean [ 65 ], cotton [ 25 ], maize [ 29 , 66 ]; Phaseolus vulgaris [ 67 ], sweet potato [ 68 ], and basil [ 69 ] further corroborated our results, such as a reduction in total leaf area and fresh and dry weights, number of leaves, and height of plants ( Table 3 ) under higher UV-B levels. In contrast to our results, Sakalauskaite et al [ 70 ] reported an increase in plant height, leaf area, and dry weight under elevated UV-B in Ocimum basilicum .…”