TITLE:
Agrobacterium-Mediated Transformation of Selected Kenyan Maize (Zea mays L.) Genotypes by Introgression of Nicotiana Protein Kinase (npk1) to Enhance Drought Tolerance
AUTHORS:
John Vincent Omondi Muoma, Omwoyo Ombori
KEYWORDS:
Agrobacterium tumefaciens; Drought Tolerance; Nicotiana Protein Kinase; Southern Blot Hybridization; Zea mays
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.6,
March
25,
2014
ABSTRACT: Currently maize
production in the East and Central Africa (ECA) region is at 1.3 tonnes per
hectare compared to the potential of up to 7.0 tonnes
per hectare because of biotic and abiotic constraints, and this has resulted in prevalence
of famine in sub-Saharan Africa. Drought is the most important abiotic stress
affecting productivity of maize in Sub Saharan Africa leading to up to 70% crop
loss and in certain cases total crop loss. Previous work has shown that
Mitogenic Activated Protein Kinase (MAPKKK) gene activated an oxidative signal cascade, which led to tolerance to adverse condition. To
analyze the role of the oxidative signal cascades on tropical maize, 4
transgenic tropical maize plants were developed through an Agrobacterium-mediated transformation with a MAPKKK homology from tobacco Nicotiana Protein Kinase 1 (npk1) and the insert was confirmed using
Southern and Northern blot hybridization analysis. Fertile To maize
plants were obtained which were planted to generate T1 plants,
which were used for comparison with non-transgenic plants. The T1 plantlets of tropical inbred TL08-(2)4, single hybrid cross of a PTL001, a
multiple cross hybrid DH01 and a dry land cultivar DLC1 genotypes were planted
in the greenhouse and assessed for morphological and physiological changes
associated with increase in drought stress tolerance when under water stress
condition. The results showed that npk1 effectively
enhanced drought tolerance in TL08-(2)4 and PTL001, and there was no
significant morphological difference between transgenic
controls (well watered) and transgenic tests (subjected to moderate drought
stress). Overall, there were between 20%-35%
enhancements of yield of the transgenic stressed events compared with non-transgenic
stressed control.