1a.Objectives (from AD-416):
A research group led by the ADODR at ARS and collaborators from Embrapa (Brazil), JIRCAS (Japan), IRRI (Phillipines) and Moi University (Kenya) have come together to work on maize adaptation to acid soils that limit maize yields on acid soils that are widespread throughout the world and particularly in sub-Saharan Africa. The group will work to identify genes that confer tolerance to the abiotic stresses that occur on acid soils, particularly aluminum toxicity and phosphorous deficiency, and this molecular information will be used within a molecular breeding program to improve maize for agriculture on acid soils.
1b.Approach (from AD-416):
The research team is using a multidisciplinary approach to identify maize genes that confer tolerance to aluminum (A1) toxicity and phosphorous (P) deficiency that limit maize yields on acid soils. Molecular, genomic, genetic and physiological approaches will be used to identify the genes and associated physiological mechanisms for tolerance to A1 toxicity and P deficiency. The specific tolerance traits to be studied will be the ability for roots to grow in A1 toxic soils, the ability to modify the whole root architecture to acquire P from the acid soil, and the ability to maintain higher yields on low P and/or A1 toxic soils. A comparative genomics approach will be used to look for maize genes that are similar in sequence and function to sorghum A1 tolerance and rice P efficiency (tolerance to P deficiency) genes that our group already has discovered. Once these A1 tolerance and P efficiency genes in maize have been identified and verified, we will identify molecular markers that are diagnostic for the best versions of these genes for use in maize molecular breeding programs for acid soil tolerance in Africa.
In FY 2012, we have been studying maize genes that are homologs of the phosphorous uptake gene in rice, Pup1, which is a protein kinase. We have identified a family of six maize kinase genes which we will investigate for their role in maize phosphorous efficiency (tolerance to low P in the soil).