2012 Dryland Field Day Abstracts - Dept. of Crop and Soil Sciences ...

Part 1. Breeding, Genetic Improvement, and Variety Evaluation Page 25
(http://variety.wsu.edu). Oral presentations, field days, and industry
and extension meetings are other means used for delivering research
results. Results from the Extension Variety Testing Program provide
independent assessment of variety performance to support variety
selection decisions by growers and for other decisions by other
clientele. Growers can realize a timely economic payback using
information from yield and variety performance data that is provided
within days after harvest via an email list-serve. This project is made
possible by contributions of land and time from farmer cooperators
where trials are located, and cooperators at the WSU research units
at Pullman and Lind. Partnerships with research scientists from public
and private sectors are vital to make this program successful. Funding
is provided by: Washington Grain Commission, Dry Pea and Lentil
Council, WSU Agricultural Research Center, and Washington State
Crop Improvement Association.
Modification of Coleoptile Length in Wheat Via Manipulation of the AHL Gene Family
Michael M. Neff, David Favero, Pushpa Koirala, Jiwen Qiu and Jianfei Zhao
Dept. of Crop and Soil Sciences and Molecular Plant Sciences Graduate Program, WSU
In low rainfall, dryland-cropping areas of Eastern Washington stand establishment can have a major impact on yields of winter
wheat. The problem is especially prevalent in these areas as winter wheat is generally planted in the last part of August or early in
September. During dry years these seeds need to be planted in deep furrows (up to 8”) so that the developing seedling has access
to ground water. To facilitate stand establishment, wheat breeders have been trying to develop varieties with long coleoptiles as
seedlings while maintaining a high-yielding semi-dwarf stature as adults. Unfortunately, few mechanisms have been identified that
uncouple the semi-dwarf phenotype of adult plants with reduced elongation of the coleoptile in seedlings. The Neff lab has
identified a group of plant-specific genes that, when mutated in a particular way, uncouple seedling elongation from adult size.
These genes encode AHL (AT-Hook Containing, Nuclear Localized) proteins have two domains. One domain, the AT-Hook, binds ATrich
regions of DNA. The second domain is involved in protein/protein interactions.
This project includes three main objectives: 1) to identify AHL family members in wheat, 2) to identify those genes that are
expressed at high levels in the coleoptile, and 3) to examine the role of both wild type and mutant genes on coleoptile elongation.
In addition to the identification of many partial AHL sequences, we have cloned four full-length AHL sequences from the wheat
genome and named them Taq1, Taq2, Taq3, and Taq4. These sequences were identified using a combination of comparative
genomic and PCR cloning techniques. The four wheat AHL sequences were constructed into both prey and bait vectors for yeasttwo-hybrid
analysis, which allows us to test protein-protein interactions amongst the family members. The results show that the
wheat AHL proteins Taq2 and Taq3 interact to each other. We have also shown that Taq2 and Taq3 can also interact with the
Arabidopsis AHL SOB3 protein. These results strongly suggest that the biochemical function of AHL proteins can be conserved
between dicot and monocot species. RT-PCR reactions have been done for Taq2, Taq3 and Taq4 at early stages of plant
development. In addition to confirming expression of each gene in coleoptiles, the results revealed differential expression patterns
for Taq2, Taq3, and Taq4 in the early stages of wheat seedling development. Immature wheat embryos (14-16 days after
flowering) were used as explants to induce callus for transformation of mutant and wild type wheat AHL sequences (Figure 1). This
transgenic approach will allow for phenotypic analysis of agronomic traits for wheat expressing different forms of these genes.
Fig. 1. Wheat callus used for transformation of wildtype and mutant forms of AHL genes. Close
up (left). Growth chamber with many wheat transformation experiments (right).