The Graduate School of Universitas Gadjah Mada proudly announces the graduation of Ayu Lestiyani, a doctoral student from the Biotechnology Study Program, batch 2021 (odd semester). Ayu successfully defended her dissertation on Identification of Citrus Relative, Murraya spp., and Gene Expression Analysis on Citrus and Murraya Against Serralysin Toxin of Candidatus Liberibacter asiaticus, supervised by an international team of promoters.
Her dissertation was guided by Prof. Dr. Siti Subandiyah and Prof. Dr. Tri Joko from Universitas Gadjah Mada, and co-promoted by Prof. Dr. Toru Iwanami from Tokyo University of Agriculture (NODAI), Japan. The dissertation examination committee included Dr. Alan Soffan and Dr. Widhi Dyah Sawitri (both from the Faculty of Agriculture, UGM), Prof. Rina Sri Kasiamdari (Faculty of Biology, UGM), and Dr. Kikin Hamzah Mutaqin (IPB University, Bacteriology). The final examination was chaired by Dr. Techn. Khabib Mustofa, S.Si., M.Kom., Vice Dean of the Graduate School.
As part of her research, Ayu conducted a portion of her study at Tokyo University of Agriculture (NODAI), Japan, where she performed whole chloroplast genome sequencing (WGS) of several Murraya species to support the phylogenetic and taxonomic analyses. This collaborative effort strengthened the molecular approach in clarifying the evolutionary relationships among Murraya species in Indonesia.
Ayu’s research focused on clarifying the taxonomic status and disease susceptibility of Murraya species, particularly their role as alternative hosts for Candidatus Liberibacter asiaticus (CLas), the pathogen responsible for Huanglongbing (HLB) disease in citrus. Her study confirmed, for the first time, the natural infection of Murraya sumatrana in Java, providing critical data for quarantine and management strategies. In addition, she analyzed the expression of a serralysin-like gene, a suspected virulence factor in CLas, and investigated molecular defense mechanisms in both citrus and Murraya species. The findings suggest that certain Murraya species possess more effective immune responses compared to citrus, which could support the development of sustainable HLB management approaches.
Her work was supported by the ACIAR (Australian Centre for International Agricultural Research) project, led by her supervisory team, further emphasizing the strong international collaboration and capacity building aspects of her research.
The significance of Ayu’s research is further highlighted by her publication in the prestigious journal Plant Disease (Volume 108, 2024), titled Natural Infection of Murraya paniculata and Murraya sumatrana with ‘Candidatus Liberibacter asiaticus’ in Java, indexed in Scopus Q1. This publication demonstrates the international relevance and scientific impact of her work.
Importantly, Ayu’s research contributes to achieving the United Nations Sustainable Development Goals (SDGs), particularly Goal 2 (Zero Hunger) and Goal 15 (Life on Land), by promoting plant health, safeguarding citrus production, and enhancing sustainable agricultural practices.
Universitas Gadjah Mada congratulates Ayu Lestiyani on her remarkable achievements and wishes her continued success in her future academic and professional endeavors. Her dedication and contributions exemplify the university’s commitment to advancing biotechnology research for the benefit of society.