College of Agriculture & Natural Resources Department of Horticulture

Fundamental/Molecular biology

Dr. Sean Cutler, Distinguished Professor
Botany and Plant Sciences Department
UC Riverside, USA

Sean Cutler is a plant biologist recognized for his work on the hormone abscisic acid (ABA), which is a stress-activated signaling molecule that helps plants cope with drought stress. Dr. Cutler was born in Canada and graduated from the University of Toronto with degrees in anthropology (B.A.) and botany (M.S.), and from Stanford University in biological sciences (Ph.D.). After brief postdoctoral studies at the Scripps Research Institute, Dr. Cutler became an Assistant Professor at the University of Toronto and subsequently moved to UCR in 2006. He is currently a Distinguished Professor of Plant Cell Biology in the Department of Botany and Plant Sciences, a Fellow of the American Association for the Advancement of Science (2017), and a member of the National Academy of Sciences (2018). He has won multiple awards for his research including the American Society of Plant Biologists' Charles Albert Shull Award (2011) for outstanding contributions to plant biology.

Dr. Cutler's research focuses on understanding and manipulating plant responses to drought. His laboratory uses a combination of chemical, biochemical, and genetic approaches to dissect the mechanism of action of ABA, a central regulator of plant stress responses. When Dr. Cutler started his laboratory, a long-standing and unresolved question was: how is ABA perceived? Previous attempts to answer this question using mutational analyses had turned up empty-handed. We now know, due to Dr. Cutler's work and that of others, that this is because multiple receptors perceive ABA. As a result, removing any single receptor is not sufficient to disrupt signaling on its own, which hampered genetic analyses. Dr. Cutler's laboratory took a chemical approach to the problem and identified a synthetic ABA mimic called pyrabactin, which selectively activates a subset of ABA responses. His group then used pyrabactin as a form of biochemical "bait" and used it to identify the first ABA receptor. This pivotal discovery has opened the door to both chemical and genetic improvement of crop tolerance to drought. His lab has since developed synthetic ABA mimics to serve as next-generation agrochemical tools for mitigating the effects of drought stress on agriculture. More recently, his laboratory has used synthetic biology approaches to reprogram plants so that traits of interest, such as drought tolerance or flowering can be controlled at will with environmentally benign chemicals.

Application Technologies and Environmental Regulation of Bioregulator Penetration

Dr. John Bukovac (1929-2025), Michigan State University, in memoriam presented by Dr. Peter Petracek

Martin John Bukovac: Career and Concepts

Dr. Martin John Bukovac, University Distinguished Professor Emeritus in the Horticulture Department at Michigan State University (MSU), died Sunday January 5 2025 in East Lansing, Michigan. John was born in the rough coal-mining town of Johnson City in southern Illinois on November 12, 1929. His family moved to a fruit and vegetable farm near Paw Paw, Michigan when he was 10 years old. John went on to earn his BS, MS, and PhD in Horticulture from MSU. During the Cold War, John served as a US Army tank unit commander along the West/East German border. John noted that his military training was essential to the development of his approach to research and communication: organized, focused, and direct.

John joined the Horticulture Department faculty at MSU in 1957. Over the next 40 years, John was the advisor to 18 M.S. and 17 Ph.D. students and mentored 41 postdoctoral students and visiting scientists. John’s career was dedicated to development of plant growth regulators for fruit tree growers to improve the quality of their crop and the profitability of their farm. His approach was to focus on fundamental aspects of horticulture and translate those findings to meaningful applications within the fruit industry. His laboratory pioneered research on apple and cherry fruit physiology, commercial uses of plant growth regulators, the fundamentals of cuticular penetration, and spray application technology. His research and guidance eventually led to the commercialization of ethephon for cherry abscission, gibberellic acid for pasture grass production, abscisic acid for grape coloration, an improved benzyladenine formulation, and aminocyclopropane carboxylyic acid for apple and stone fruit thinning. John’s pioneering work continues to impact the fruit industries.

John’s contributions to science in general and to the agriculture industry in particular earned him numerous scientific awards including membership in the National Academy of Sciences. As a scientist, John dedicated his career to the advancement of the Michigan apple and cherry fruit industries. In 2016, he generously endowed the Martin and Judith Bukovac Professorship in Tree Fruit Physiology in the College of Agriculture and Natural Resources at MSU to support a faculty position focused on the study of applied tree fruit research and outreach to the industry. John actively mentored students and faculty in the Horticulture Department even after his retirement in 1996, continuing to influence future leaders in horticultural science as recently as 2024.

At the June 2025 ISHS meeting in Chicago, John’s career will be presented along with select concepts on research.

Dormancy

Dr. Yuanwen Teng, Professor

College of Agriculture and Biotechnology, Zhejiang University, China

Dr. Yuanwen Teng is a professor in the College of Agriculture and Biotechnology, Zhejiang University, China. He serves on the editorial board of BMC Plant Biology, Horticulturae and other journals, and is the vice president of the Pear Branch of the Chinese Society for Horticultural Science. He has been engaged in research on fruit tree germplasm resources and breeding, plant genetic diversity, molecular mechanism of fruit color and quality formation, and dormancy regulation in fruit trees. He has published more than 190 papers in peer-reviewed journals, including The Plant Cell, Plant Physiology, Plant Biotechnology Journal, New Phytologist, The Plant Journal, Plant, Cell & Environment, Journal of Experimental Botany, Horticulture Research, etc. In the study of fruit tree dormancy, Dr, Teng and his group used pear as experimental material and proposed a molecular regulatory model of pear bud dormancy centered on the DAM (dormancy-associated MADS-box) gene, in which the DAM transcription factor regulates the maintenance and release of dormancy by integrating ABA signaling and GA biosynthesis and catabolism. In addition, epigenetic regulation and crosstalk between the BR and JA pathways also play important roles in the maintenance and release of dormancy in pear buds.

Vegetative and Reproductive Growth and Development

Dr. Tripti Vashisth, Associate Professor and Associate Center Director
Citrus Research and Education Center, University of Florida, USA

Our lab focuses on fruit production in Florida, emphasizing citrus. The primary focus of my research program is on flowering, fruit set, growth, and development in citrus, from physiology to molecular level. Currently, Florida citrus industry is struggling due to bacteria disease, Huanglongbing (HLB/citrus greening), hence my research program currently addresses developing horticultural strategies for improving citrus production under HLB-prevalent conditions. Plant growth regulators are an excellent tool to manipulate flowering and fruiting thus, we are constantly working with different PGRs. We have recently, demonstrated that exogenously applied gibberellic acid can improve the yield and productivity of HLB-affected sweet orange trees by improving source to sink ratio as well as mitigating oxidative stress in trees. Our lab currently focuses on several PGRs that can potentially mitigate biotic and abiotic stress in citrus trees. In addition to developing field ready solutions for the growers, we also explore the mode of action/mechanism of PGRs to enhance our understanding of plant hormones in fruit crops.

Fruit Maturation and Harvest

Dr. Islam El-Sharkawy, Associate Professor
College of Agriculture & Food Sciences (CAFS) and Center for Viticulture & Small Fruit Research (CVSFR), Florida A&M University (FAMU)

Islam Sharkawy serves as an Associate Professor of Grape Breeding and Fruit Crop Production at Florida A&M University. He is a renowned expert in tree fruit biology, focusing on fruit ripening and postharvest biology. His extensive experience spans numerous universities, governmental institutions, and non-profit organizations in Egypt, France, Canada, and the United States. Dedicated to addressing biological, environmental, and genetic challenges, Dr. Sharkawy aims to enhance the sustainability and profitability of the tree fruit industry. His research seamlessly integrates both fundamental and applied sciences, blending theoretical knowledge with practical fieldwork. He is particularly interested in the factors that influence fruit development, delving into the molecular and biochemical mechanisms behind fruit ripening and extending shelf life.

Postharvest biology

Dr. Zora Singh, Foundation Professor Horticultural Science
Edith Cowan University, Australia 

Professor Singh, a distinguished researcher and educator, is a fellow of leading horticultural science academies. With over 30 years of research, he has advanced the hormonal physiology of fruit crops, his pioneering work includes developing ethylene antagonists, improving apple colouration, and enhancing storage for mangoes and plums. His work, recognized with 10 global awards, has significantly impacted horticulture. He also established teaching and research programs at Curtin and Edith Cowan Universities, earning prestigious awards for excellence in postgraduate supervision and teaching. Professor Sing will present on the current status of jasmonates for enhancing fruit quality and storage life via preharvest and postharvest applications.