Antioxidant system is essential to increase drought tolerance of sugarcane. (11th October 2017)

• Record Type: Journal Article
• Authors: Vilela, R.D.; Bezerra, B.K.L.; Froehlich, A.; Endres, L.
• Is Part Of: Annals of applied biology. Volume 171:Number 3(2017)
• Page Start: 451
• Page End: 463
• Publication Date: 2017-10-11
• Subjects: Antioxidant activity -- photoinhibition -- ROS -- Saccharum -- water stress; Crop science -- Periodicals; Plants, Protection of -- Periodicals; Crops -- Ecology -- Periodicals; 630
• DOI: 10.1111/aab.12387
• Languages: English
• ISSNs: 0003-4746

Abstract

Abstract : Two varieties of sugarcane ( Saccharum spp.) with contrasting responses to drought (RB867515, more tolerant; and RB855536, less tolerant) were subjected to progressive drought conditions (2, 4, 6 and 8 days) followed by rehydration. Several physiological parameters were measured: leaf water potential and osmotic potential; leaf carbon metabolism; maximum and effective PSII quantum yield; and antioxidant enzymes. The results suggest that RB867515 is more tolerant to drought conditions because of a more efficient antioxidant system, which results in reduced photosynthesis photoinhibition during water stress, thus revealing itself as a potential physiological marker for drought tolerance studies. Abstract: Drought is one of the main factors affecting the productivity of agricultural crops, and plants respond to such stress by activating various physiological and biochemical mechanisms against dehydration. The present study investigated two varieties of sugarcane ( Saccharum spp.) with contrasting responses to drought (RB867515, more tolerant; and RB855536, less tolerant) and subjected them to progressive drought conditions (2, 4, 6 and 8 days) followed by rehydration. Drought caused a decrease in water potential (ψw ) and osmotic potential (ψos ) in the leaves, which recovered to normal levels after rehydration only up to the fourth day of drought. Water stress changed the carbon metabolism of leaves by reducing starch and sucrose contents and increasing glucose and fructose contents in both varieties. Water deficit caused a significant reduction in the maximum quantum efficiency of photosystem II (Fv /Fm ) and effective quantum yield (ΦPSII ) in both varieties; however, RB867515 recovered faster after rehydration. Under water stress, the more tolerant variety RB867515 exhibited increased activity of the antioxidant enzymes catalase, ascorbate peroxidase and superoxide dismutase compared with the RB855536 variety. The results suggest that RB867515 is more tolerant to drought conditions because of a more efficient antioxidant system, which results in reduced photosynthesis photoinhibition during water stress, thus revealing itself as a potential physiological marker for drought tolerance studies.