Environmental abiotic stresses, such as cold, drought, and high salinity, can greatly affect plant growth and development. Plant scientists have faced increasingly challenging climate changes to maintain and increase the food production in the world. Due to their sessile nature, plants have to develop special systems to respond and adapt to stresses and ultimately acquire stress tolerance for survival. Thus, understanding mechanisms for stress adaptation and tolerance is one of the most important and challenging goals in plant sciences and holds the key for future plant breeding. One of our main ongoing research projects is to identify plant “enhancers” that regulate expression of genes activated by abiotic stresses. Enhancers are cis-regulatory DNA elements that control the expression of genes during specific developmental stages or under various biotic and abiotic stresses. Enhancers can be identified based on their unique molecular signatures associated with open chromatin (2021, Plant Cell 33: 1997-2014). Identification and characterization of stress-responsive enhancers will be essential for us to understand plant stress biology, such enhancers will also become a key resource to improve the tissue specificity and transcription levels of transgenes for crop improvement.
A cold-inducible enhancer in Arabidopsis thaliana. The two transgenic plants carry the same T-DNA insertion composed of an enhancer fused to the GUS reporter gene. Left: GUS assay of a two-week-old seedling grown under room temperature. Right: GUS assay of a seedling placed under 4℃ for 24 hours prior to GUS staining. Note: GUS signals were mainly observed in roots and main veins before cold treatment. GUS signals can be observed in the entire seedling after cold stress.
Potato improvement via genetic mapping and biotechnology
Potato is the third most important food crop in human consumption, next to rice and wheat. Our lab is interested in developing new potato cultivars by discovery and manipulation of genes associated with key agronomic traits. We are investigating physiological traits such as tuber size and tuber sprouting, and traits associated with potato processing quality, including cold-induced sweetening (Zhu et al. 2016, Plant Biotech. J. 14: 709-718). By implementing state-of-the-art genetic mapping approaches, our group has identified several candidate genes associated with these traits. We are currently in the process of validating the functional roles of these candidate genes. Allelic variation at critical agronomic genes, especially in wild Solanum species, provides an important resource to improve modern cultivars. Our lab is actively exploring the extent, function, and influence of these natural variants and their applicability towards crop improvement in potato. The genetic and genomic information harbored within these genes will be essential for future breeding and genomic selection efforts. Our group utilizes cutting-edge technologies, such as CRISPR/cas, to generate sequence variants within potato genes, which can supplement natural variants and even create novel allelic combinations. In parallel, we are developing enhancers maps under various stress and developmental conditions. One of our long-term goals is to combine tissue-specific and stress-inducible enhancers with important potato genes, allowing us to improve the agronomic performance of potato under any given environmental condition.
Potato heterosis. The middle row reflects F1 potato hybrids derived from highly homozygous female (left row) and male (right row) parental lines. The F1 plants show extremely high levels of heterosis in both plant vigor and tuber size.
Jiang Lab
