I have an appointment of research and extension in nutrition physiology and stress physiology of deciduous fruit crops with emphasis on apples and grapevines. The goal of my research programs is to better understand the physiological processes underlying carbon/mineral nutrition and environmental stresses on plant growth, fruiting and fruit quality and develop management practices for improving orchard productivity and fruit quality. I am also involved in undergraduate and graduate teaching.
The interaction between carbon and nitrogen dominates the primary metabolism in plants, and therefore elucidating this interaction is critical for understanding the physiology of the whole plant. We are currently focused on how nitrogen supply affects carbon metabolism and nitrogen metabolism in both apples and grapes. Pome and stone fruits of the Rosaceae family, such as apple and cherry, are unique in that sorbitol serves as a primary end-product of photosynthesis and a major translocated carbohydrate in the phloem. Sorbitol is also implicated in responses to environmental stresses. We are using apple trees with decreased sorbitol synthesis to understand the role sorbitol plays in carbohydrate metabolism, organic acid metabolism and nitrogen metabolism, and stress tolerance. We are very interested in both primary metabolism and secondary metabolism relevant to fruit quality during fruit growth and development as well as their responses to nutrient stress and other environmental stresses. Sugar/acid accumulation and metabolism in apple fruit is one of the foci of our current work. On the more applied side, our research addresses uptake, translocation, storage, and remobilization and demand-supply relationship of nitrogen and other nutrients in apples and grapevines to provide basis for optimizing nutrient inputs into both apple orchards and vineyards.
Outreach and Extension Focus
The goal of my extension program is to effectively deliver research-based, up to date information and provide expertise concerning nutrient management to the apple and grape industries in New York through collaborations with faculty, extension educators, and growers. My extension activities are closely tied with my applied research. The current focus is management of nitrogen, potassium, calcium and other essential nutrients to improve yield and quality of high density apple plantings.
My goal in teaching and advising is to train students so that they develop to realize their academic potential, resulting in not only getting a degree from Cornell, but more importantly becoming a “thinker” and a “doer” in the field of horticultural sciences.
My teaching has been largely in mineral nutrition of fruit crops and advanced analytical techniques in plant science.
- Bai, Y., Dougherty, L., Cheng, L., Zong, G., & Xu, K. (2015). Uncovering co-expression gene network modules regulating fruit acidity in diverse apples. BMC Genomics. 16.
- Wu, T., Wang, Y., Zheng, Y., Fei, Z., Dandekar, A., Xu, K., Han, Z., & Cheng, L. (2015). Suppressing sorbitol synthesis substantially alters the global expression profile of stress response genes in apple (Malus domestica) leaves. Plant Cell Physiology.
- Li, P., Zhang, Y., Einhorn, T. C., & Cheng, L. (2014). Comparison of phenolic metabolism and primary metabolism between green 'Anjou' pear and its bud mutation, red 'Anjou'. Physiologia Plantarum. 150:339-354.
- Feng, F., Li, M., Ma, F., & Cheng, L. (2013). Phenylpropanoid metabolites and expression of key genes involved in anthocyanin biosynthesis in the shaded peel of apple fruit in response to sun exposure. Plant Physiology and Biochemistry. 69:54-61.
- Li, P., Ma, F., & Cheng, L. (2013). Primary and secondary metabolism in the sun-exposed peel and the shaded peel of apple fruit. Physiologia Plantarum. 148:135-152.
- Bai, Y., Dougherty , L., Li, M., Fazio, G., Cheng, L., & Xu, K. (2012). A natural mutation-led truncation in one of the two aluminum-activated malate transporter-like genes at the Ma locus is associated with low fruit acidity in apple. Molecular Genetics and Genomics. 287:663-678.
- Li, M., Feng, F., & Cheng, L. (2012). Expression patterns of genes involved in sugar metabolism and accumulation during apple fruit development. PLoS One. 7:e33055.
- Fu, Q., Cheng, L., Guo, Y., & Turgeon, E. G. (2011). Phloem loading strategies and water relations in trees and herbaceous plants. Plant Physiology. 157:1518-1527.
- Wang, H., Ma , F., & Cheng, L. (2010). Metabolism of organic acids, nitrogen and amino acids in chlorotic leaves of ‘Honeycrisp’ apple (Malus domestica Borkh) with excessive accumulation of carbohydrates. Planta. 232:511-522.
- Cheng, L., & Raba, R. M. (2009). Accumulation of macro- and micronutrients and nitrogen demand-supply relationship of ‘Gala’/M.26 trees grown in sand culture. Journal of the American Society for Horticultural Science. 134:3-13.