Data/hora: 23/09/2024 05:55:16

Biblioteca(s): 	Embrapa Milho e Sorgo.	
Data corrente: 	10/11/2017	
Data da última atualização: 	16/11/2017	
Autoria: 	MATONYEI, T. K; SIRMAH, P. K.; SITIENEI, A. J.; OUMA, E. O.; LIGEYO, D. O.; CHEPROT, R. K.; MARITIM, K. K.; WERE, B. A.; KISINYO, P. O.; GUDU, S. O.; MAGALHAES, J. V.; GUIMARAES, C. T.; KOCHIAN, L. V.	
Afiliação: 	University of Kabianga; University of Kabianga; University of Kabianga; Rongo University College; KALRO-Kitale; University of Eldoret; University of Eldoret; University of Eldoret; Rongo University College; Rongo University College; JURANDIR VIEIRA DE MAGALHAES, CNPMS; CLAUDIA TEIXEIRA GUIMARAES, CNPMS; USDA-ARS, Cornell University.	
Título: 	The expression of ZmMATE1 gene at seminal root tip does not explain aluminum toxicity tolerance in a Kenyan maize breeding line.	
Ano de publicação: 	2017	
Fonte/Imprenta: 	International Journal of Scientific Research and Innovative Technology, v. 4, n. 3, p. 45-59, 2017.	
Idioma: 	Inglês	
Conteúdo: 	Aluminium toxicity prevalent in acid soils is a major limitation to crop production worldwide. Under low pH, the rhizotoxic Al3+ ions are released from insoluble ores into the soil solution. Upon absorption into root cells, they cause root rigidity disrupting cell division and cell elongation hence limiting root growth. This predisposes the plant to drought and nutrient deficiencies consequently causing low yield production. Few candidate genes for Al tolerance have been identified in maize, these include, ZmMATE1, ZmMATE2 and ZmNrat1. The expression of these genes among Kenyan maize is not well known. This research was done with the following specific objectives; (i) to determine the Al toxicity tolerance of selected Kenyan maize breeding lines and (ii) to determine the expression of ZmMATE1 gene in selected Kenyan maize lines. Two hundred and thirty five (235) and 40 selected Kenyan maize breeding lines were screened for Al tolerance and expression of ZmMATE1 gene at the seminal root tip respectively. At 39 &#956;M Al3+ activity in nutrient solution culture, 1.7% of breeding lines exhibited a stimulated growth; 2.55% showed almost no effects while 10.21% reported mild effects of the toxic cation on their root growth. At this Al activity 14%, 20%, 12% and 3% showed root growths of below 48%, 39%, 29% and 19% respectively. With reference to the calibrator, ZmMATE1 expression levels were as high as 16 fold in the Breeding line SYN AL × R12C10 ? 8 and as low as 0.54 fold in the Breeding line MUL 891. The mean expression level of the gene among the 40 breeding lines was 2.64 fold. Two Breeding lines, CATAL 237/167 × L3 ? 5 and SYN AL × R12C10 ? 8 that are inbred lines derived from crosses between germplasm from Kenya(KALRO) and Brazil(EMBRAPA ? Maize and Sorghum) exhibited the highest expression levels. Other Breeding lines derived from other germplasm from these institutions, however, exhibited low expression levels (< 2 fold). The Breeding line ATPS4SINT1W×R12C10? 5 reported exceptionally high activity levels of the gene (> 14 fold). Most of the Breeding lines from Kenya including 203B-14 which exhibited high root growth under 39 &#956;M Al3+ activity , however, exhibited exceptionally low levels (< 2 fold) of the ZmMATE1 expression. This indicates that the expression of ZmMATE1 gene at the seminal root tip alone cannot explain Al tolerance in this breeding line. The Breeding line is thus a potential source of novel Al tolerance gene in maize.	
Palavras-Chave: 	Quênia; Tolerância ao alumínio; Toxicidade.	
Thesagro: 	Gene; Milho.	
Categoria do assunto: 	G Melhoramento Genético	
Registro original: 	Embrapa Milho e Sorgo (CNPMS)	
Exemplares: 	CNPMS - (27950-1) - UPC - AP - DD -  -  -  - DIS