| Autor: |
Matonyei TK; University of Kabianga, Agroforestry and Rural Development Department, P.O. Box 2030-20200, Kericho, Kenya., Barros BA; Embrapa Milho e Sorgo, Rodovia MG 424 km 65, Sete Lagoas, 35701-970, Brazil., Guimaraes RGN; Universidade Federal de São João del Rei, Campus Sete Lagoas, Rodovia MG 424 km 47, Sete Lagoas, 35701-970, Brazil., Ouma EO; Rongo University, P.O. Box 103-40404, Rongo, Kenya., Cheprot RK; University of Eldoret, P.O. Box 125-30100, Eldoret, Kenya., Apolinário LC; Faculdade Ciências da Vida, Av. Prefeito Alberto Moura, 12632, Sete Lagoas, MG, Brazil., Ligeyo DO; Kenya Agricultural Research Institute, P.O. Box 450-30200, Kitale, Kenya., Costa MBR; Universidade Federal de Minas Gerais, Departamento de Biologia Geral, Av. Antônio Carlos, 6627, Belo Horizonte, 31270-901, Brazil., Were BA; University of Eldoret, P.O. Box 125-30100, Eldoret, Kenya., Kisinyo PO; Rongo University, P.O. Box 103-40404, Rongo, Kenya., Onkware AO; Rongo University, P.O. Box 103-40404, Rongo, Kenya., Noda RW; Embrapa Milho e Sorgo, Rodovia MG 424 km 65, Sete Lagoas, 35701-970, Brazil., Gudu SO; Rongo University, P.O. Box 103-40404, Rongo, Kenya., Magalhaes JV; Embrapa Milho e Sorgo, Rodovia MG 424 km 65, Sete Lagoas, 35701-970, Brazil., Guimaraes CT; Embrapa Milho e Sorgo, Rodovia MG 424 km 65, Sete Lagoas, 35701-970, Brazil. claudia.guimaraes@embrapa.br. |
| Abstrakt: |
Aluminum (Al) toxicity on acid soils adversely affects maize yields, which can be overcome by combining soil amendments with genetic tolerance. In maize, ZmMATE1 confers Al tolerance via Al-activated citrate release, whereby citrate forms non-toxic complexes with Al 3+ in the rhizosphere. Here, we investigated Al tolerance mechanisms in maize germplasm originated from Kenya based on quantitative trait loci (QTL) mapping. Five QTLs and four epistatic interactions explained ~51% of the phenotypic variation for Al tolerance. The lack of Al tolerance QTL on chromosome 6 and the much lower expression of ZmMATE1 in both Kenyan lines than in Cateto Al237, which donates the superior allele of ZmMATE1, strongly indicate that this gene does not play a significant role in Al tolerance in neither parent. In turn, maize homologs to genes previously implicated in Al tolerance in other species, ZmNrat1, ZmMATE3, ZmWRKY and ZmART1, co-localized with Al tolerance QTL and were more highly expressed in the parent that donate favorable QTL alleles. However, these candidate genes will require further studies for functional validation on maize Al tolerance. The existence of Al tolerance mechanisms independent from ZmMATE1 suggests it is possible to develop highly Al tolerant cultivars by pyramiding complementary Al tolerance genes in maize. |
