Allison Krill was a technician in the group who is now a graduate student.
She has been working on aluminum tolerance of maize in conjunction with the Hoenkenga and Kochian labs. Her primary work invovles association mapping of candidate genes involved in Al tolerance, which were selected using comparative and physiological genomics-based approaches.
Aluminum toxicity is a global issue
Aluminum (Al) toxicity is a major constraint to maize productivity on acidic soils throughout the world. Phototoxic Al becomes soluble at pH < 5.5, inhibiting root growth and function, thus severely reducing yields. In countries where soil amelioration is not an economically feasible option, breeding maize for tolerance would provide an inexpensive, sustainable solution to the problem.
Right: World soil pH map. Areas of red and orange susceptible to Al toxicity. 2006 WSRIC - World Soil Information.
Above: Photo from Vera Alves - Embrapa Maize and Sorghum. Two maize lines, varying for aluminum tolerance, grown in acidic soil. Yield reduced 30-100%
Right: maize seedlings varying for Al tolernace after two days stress in hydroponics
Effects of soluble Aluminum on plants:
- Inhibition of root growth
- limited water and nutrient uptake
- Inhibition of root cell expansion and elongation
- Disruption of cytoskeleton dynamids
- Increased susceptiblility to drought, pests, and disease
Phenotyping for aluminum tolerance
The greatest effect of toxic aluminum on plants is inhibited root growth.
The measurement of root growth in an aluminum toxic solution was used to quantify tolerance levels.
Seedlings were growth for 48 hrs in a complete high ionic strength nutrient solution at pH 4.0 containing Al.
