Aluminum-induced stress differently modifies Urochloa genotypes responses on growth and regrowth: root-to-shoot Al-translocation and oxidative stress

作者：Furlan Felipe; Borgo Lucelia; Silveira Rabelo Flavio Henrique; Rossi Monica Lanzoni; Martinelli Adriana Pinheiro; Azevedo Ricardo Antunes; Lavres Jose^*

来源：Theoretical and Experimental Plant Physiology, 2018, 30(2): 141-152.

DOI：10.1007/s40626-018-0109-2

• Brachiaria
• GeoChem
• Malondialdehyde
• Lipid peroxidation
• Relative root growth

Forage grasses belonging to the Urochloa (Brachiaria) genus present tolerance to A1 toxicity, however there are intra- and interspecific differences among the species, which in turn should be better depicted. Here we evaluate genotypic differences in A1 tolerance in four Urochloa (U. decumbens cultivar Basilisk; U. brizantha cultivar Marandu; U. brizantha cultivar Piata and U. brizantha cultivar Xaraes) cultivated in nutrient solution, during growth and regrowth. We analyzed the effect of A1 uptake on epidermal and cell membrane damage, and lipid peroxidation in shoots and roots. Exposure of genotypes to A1 concentration up to 1.33 mmol L(-1)led to different degrees of shoot yield, mainly during the growth period. Increased A1 concentration decreased dry matter production in shoots and roots, reduced leaf area (LA), relative root growth, increased A1 accumulation in the roots and root-to-shoot A1 translocation, notably during the first growth period. However, A1 translocation from roots to shoots augmented massively in all genotypes, during the regrowth. Plant roots exposed to A1 were damaged, exhibiting ruptures in the epidermis and reduced number of root hairs. Lipid peroxidation in shoots ranged in all genotypes exposed to Al, however, the oxidative stress was 2-5 times higher in shoots than in roots, notably in Marandu that accumulated 95% more Al than U. decumbens. This suggests that in the genotypes that are more tolerant to Al there is maintenance of metabolic activities, including upregulated and efficient antioxidant activity, root growth, LA growth and biomass yield.

• 出版日期2018-6