Our gene function testing team examines apple, kiwifruit and blueberry genes that have useful functions for plant breeders, for example, a ripening-related function.
To prove these fruit genes do have a specified function, the team takes two main approaches: transgenics, which is deleting the gene or over expressing it in its species of origin. This is a slow and difficult process. The alternative is expressing the gene in a model plant like Arabidopsis or tobacco. These plants are smaller with a much faster life cycle. Arabidopsis, for example, reproduces in three months. In comparison, apples or kiwifruit can take up to three years to produce their first seeds.
The dangers of function testing in model plants are that the genes transferred may give an erroneous result. But in most cases, the genes are significantly homologous to each other and good results have been obtained quickly. In addition researchers can bypass apple or kiwifruit genes and take the Arabidopsis' version of the apple or kiwifruit gene of interest, and delete or overexpress it.
Gene transformation has proven to be a major revolution in plant biology. Team members have skills in physiology, biochemistry, cellular biology, crop transformation, gene cloning and sequencing, microarrays, microbiology, model plant transformation, molecular biology, genetics, gene mining, cloning, transformation of bacteria, transformation of plants, phenotyping of resulting plants, gene expression analysis (PCR, Northern, Microarrays), microscopy, and biochemical assays skills.
The team works on four key projects:
The largest project is finding apple genes that ameliorate fruit disorders, which involves establishing the stress response of apple, and studying and understanding this stress response using a microarray approach. The objective is to look at apple gene response to cold temperatures and low oxygen and from there deduce global responses. Key regulatory genes are used as markers for postharvest storage, or preharvest stress response, and allow our plant breeders to understand the apple cultivars that can store well and then use this information to produce new cultivars.
The team is characterising apple genes that control response to high temperatures, as well as the pathway that controls apple colour.
The team has external clients and interacts with several other Crown Research Institutes through the MERINET network and has developed other collaborations with Crop & Food on colour in apple and AgResearch in metabolomics. As well, the team works with researchers at the University of Auckland and Massey University.