While studied as a PhD student (1987-1990) and worked as a postdoctoral fellow (1990-1991) in Australia, Dr. He Jie had been actively involved in the research on environmental stresses (light, UV-B radiation and temperature) on photosynthesis including the properties of chloroplast and its functions, light capture, electron and ion transport, chlorophyll fluorescence and Rubisco protein. Dr. He Jie worked as a Research Fellow in the Department of Botany, National University of Singapore from January 1992 to November 1994 on a project entitled "Studies on photosynthetic characteristics, photosynthetic acclimation and photoinhibition in tropical plants". Dr. He Jie is currently an Associate Professor. Her research team has been involved in studying the physiological changes of high value vegetables by cooling the root-zone (RZ) while their aerial portions are subjected to fluctuating hot ambient temperature since she joined NIE in November 1994. Dr He Jie and her team members were also involved in studying the physiology of high value vegetables by enriching RZ CO2 while their aerial portions were subjected to constant atmospheric CO2. Performance of crops with rhizosphere manipulation was monitored using chlorophyll fluorescence and photosynthetic CO2 assimilation. The research team focused on nutrient uptake, N and C metabolism. Measuring total nitrate and organic N of plant tissues, assay of an important enzyme such as nitrate reductase had also been undertaken. C metabolism was studied by feeding 14CO2 and analyzing carbohydrates as well as the activity of sucrose phosphate synthase (SPS).
Improving the utilisation of available land area and external agricultural resources (e.g. light quality and water), via novel engineering and plant physiological solutions respectively, will deliver an efficient model of a vertical farm suitable for large scale vegetable production for the modern city such as Singapore. In 2012, Dr He Jie had received a Singapore Millennium Foundation (SMF) grant to work on “Integrated Vertical Aeroponic Farming (VAF) System: Towards Food Security and Sustainability in Singapore”. In this project, Dr He Jie’s team used an integrated VAF system with low energy input LED lighting which could increase not only cropping density per unit land area but also productivity in a cost-effective manner. Extensive development of integrated vertical aeroponic farming (VAF) systems would diminish Singapore’s reliance on vegetable imports, thus enhancing national food security.
Currently (2016 – 2019), Dr He Jie’s team is working on “Thermotolerance of temperate vegetable crops grown in the tropics: Physiological and biochemical mechanisms, productivity and quality. This research is two pronged: identifying the basal and acquired thermotolerance in selected vegetable crops and adopting sub-lethal heat stress regimes to boost adaptive thermotolerance in plants in horticultural applications. The effects of sub-lethal exposure to thermal stress (hardening) on physiology, molecular basis, productivity and quality would also be addressed.
Studying on the impacts of abiotic stresses (temperature and drought) on native tropical orchids; and physiology of orchid pseudobulbs are also Dr. He Jie’s current research interests. By understanding the mechanism(s) responsible for the photosynthetic performances of different green organs under different conditions, feasible strategies could be recommended to local nursery for enhancing the harvestable yield of tropical orchids. Understanding the response of lost native species to environmental factors would be an important step toward a sustainable conservation in Singapore. Currently, Dr He Jie is collaborating with Dr Tim W. Yam (Senior Researcher and Section Head, Conservation and Molecular Biology) in NParks on orchid conservation. She is offering short-term projects to both MLS and BSc final year students on responses of native orchids to growth irradiances and drought stress under natural conditions.
- BSc, 1982 South China Normal University, China
- MSc, 1985 South China Institute of Botany, China
- PhD 1991 Macquarie University, Australia
- PGDipTHE 1996 NTU, Singapore
- Member of the International Society for Horticultural Science (2015-present)
- Member of International Society of Photosynthesis Research (2010-present)
- Member of the Singapore Institute of Biology (1992-2016)
- Follow member of the Singapore Institute of Biology (2016-present)
- Member of the American Society of Plant Biologists (1989-present)
- Member of the Chinese Society of Plant Physiologists 1985 (Life member)
- Innovation of the Year Award 2001, Singapore on "A Tropical Process for growing temperate plants in the tropics".
- The inaugural NIE Excellence in Research Award 2016, based the outstanding contributions in extending the frontiers of research and knowledge on vertical farming of vegetable crops under LED lighting.
- License on LED-integrated vertical aeroponic farming technology (TD-271-14).
- AAB10B Physiological and Biochemical Basis of Life
- AAB10D Cell Structure and Function
- AAB30A Field Study of Ecosystem Diversity in a Changing World
- AAB30D Plant Physiology
- AAB40B Behavioural Biology
- AAB40D Academic Exercise: Biology
- ASK40A Topics in Biological Sciences for Primary Science Teaching
- QSS50D Topics in Biological Sciences for Primary Science Teaching
- MLS902 Advanced Plant Physiology
- MLS903 MLS876 Seminars on Special Topics in the Applied Plant Sciences
- Photosynthesis (chlorophyll fluorescence, Rubisco protein and carbohydrate metabolism)
- Shoot-root communication (C partitioning, nutrient uptake and N metabolism)
- Effects of Root-zone temperature and root-zone CO2 enrichment on temperate vegetable crops grown in the tropics
- Effects of LED quality and quantity on photosynthesis and vegetable production
- Physiological and nutritional studies of halophyte vegetables grown under saline condition with LED lighting
- Impact of abiotic and biotic stresses on tropical orchids
Research Grants (past 5 years)
- Thermotolerance of temperate vegetable crops grown in the tropics: Physiological and biochemical mechanisms, productivity and quality (April 2016 to April 2019)
The objectives of this proposed project are as follows:
Integrated Vertical Aeroponic Farming System: Towards Food Security and Sustainability in Singapore (October 2012 to September 2016)
- • Develop stress indices in heat stressed plants for identifying thermotolerant and thermosensitive temperate vegetable crops
- • Study the profile and kinetics of heat shock proteins (HSP) and other proteinous molecular chaperones in heat shocked plants and mechanisms of thermal tolerance conferred
- • Determine the optimal sub-lethal heat shock regime to acquire thermotolerance in vegetable cultivation and maintenance
- • Investigate the relationship among HSP and molecular chaperones production and quality and post-harvest quality of vegetables with regards to physiological parameters and nutritional value.
The objectives of this proposed project are as follows:
Understanding the Molecular Mechanism of Plant Regeneration in Tropical Aeroponic System (May 2013 to May 2017)
- • Investigate the application of LED lighting to grow different vegetable crops
- • Investigate the use of root and shoot environment differentials to improve crop productivity and quality in a cost-effective manner
- • Pilot trials and commercial application of vertical aeroponic farming technology
Root and shoot phenotyping to identify heat-resistant lettuce within recombinant inbred line populations (March 2011 to 2015)
- • Study the mechanism of plant regeneration using Arabidopsis in tropical aeroponic system.
- • Compare vegetable species with Arabidopsis for common features in regeneration
- • Apply the derived molecular knowledge on the hormone control and gene regulation to engineer synchronized regeneration process of temperate vegetables
The objectives of this proposed project are as follows:
- • Study root and shoot phenotypes and productivity in a population of 113 lettuce RILs by growing them aeroponically in a tropical greenhouse in ambient conditions, to identify heat resistant genotypes.
- • Understand the mechanistic basis of variation in heat tolerance, by measuring root architecture, plant water relations, nitrogen metabolism, photosynthetic gas exchange, and utilization of radiant energy in selected lines that differ in thermosensitivity
- • Conduct genetic (quantitative trait loci, QTL) analysis (in collaboration with geneticists at UC Davis) to identify genomic regions controlling the selected physiological variables
- • Determine whether root and shoot phenotypes are closely linked genetically
Supervision of Graduate Students and Postdoctoral Fellows
A list of postgraduate students and research staff who are currently in Dr He Jie’s laboratory/team.
- Dr Qin Lin (Research fellow) - Thermotolerance of temperate vegetable crops grown in the tropics: Physiological and biochemical mechanisms, productivity and quality.
- Tay Weiliang, Shawn (PhD student) - Physiological adaptation of some tropical orchid species to various growth conditions.
- Lai Cheng-Hsiang (Lai Chengxiang) (PhD student) - Conferment of thermotolerance to temperate vegetable crops grown under sublethal heat stress: physiological and biochemical mechanisms, productivity and quality.
- Choong Tsui Wei (PhD student).Using root phenotyping, photosynthesis, water relations and productivity of recombinant inbred lines (RIL) populations to identify heat-resistant lettuce
- Nur Estya Binte Rahman (MSc student) - Niche differentiation and ecophysiological and studies ofMyristicaceae species in Bukit Timah nature reserve and upper Seletar.
- You Xueli (MSc student) - Productivity, photosynthetic performance and nutritional values of two halophyte vegetable crops, Portulaca oleracea and Mesembryanthemum crystallinum grown under saline conditions.
A list of past graduate students
PhD students and their achievements:
- Wang Sen Zheng(2007). Impact of Abiotic and Biotic Stresses on Photoassimilate Partitioning of Tropical Orchid Plants. – Dr Wang Shen Zhang iscurrently a Researcher (China).
- Luo Hong Yi (2007). Mechanisms of Ca, P and K uptake and partitioning characteristics of certain temperate vegetables in relation to different irradiance and root-zone temperatures.Dr Luo Hong Yi is currently a full professor (China).
- Qin Lin (2004). Ontogeny, root-zone temperature and growth irradiance effects on temper ate and subtropical vegetable crops grown in the tropics. Dr Qin Lin is currently a research fellow in NIE/NTUm Singapore.
- Tan Lay Pheng (2002). Root-zone temperature effects on vegetable physiology in a commercial aeroponic system in Singapore. Dr Tan Lay Pheng is an Assistant Director, Corporate Communications.
- Flanigan-Tan Yvette (1999). Photosynthesis of Temperate plants in the tropical climate. Dr Flanigan-Tan Yvette is a senior patent scientist in Singapore.
Masters level (fulltime by research):
- Ouyang Wen (2000). Photosynthetic characteristics and carbon partitioning in the virus-eradicated and virus-infected Oncidium Gower Ramsey under different growth irradiances.
- Tan Lay Pheng (1998). Effects of different artificial topsoil on some ornamental plants.
Masters level (part-time, 6 AUs dissertation)
- Ng Si Qi Eliz. (2018)Effects of light intensity and duration on physiology, productivity, quality and tipburn in lettuce. It is supported by teaching materials’ vote of NIE/NTU.
- Qi Yun (2016) Effects of supplementary light-emitting diodes (LEDs) lighting and UVA radiation on productivity, photosynthesis and nutritional quality of aeroponically grown red and green leaf lettuce.
- Liu Yuman (2016) Photosynthetic capacities and stomatal conductance in hydroponically grown Brassica alboglabra under different combinations of blue -and red-LEDs lighting.
- Thilini alahakoon (2016). Productivity, photosynthesis and nitrogen metabolism of various leafy vegetables grown aeroponically under different combinations of light-emitting diodes (LEDs).
- Sheethal Reghu (2016) Productivity, nitrate accumulation and nutritional quality of temperate lettuce grown under different conditions in the tropical greenhouse.
- Tan Shu Hui Geraldine (2013) Photosynthetic characteristics of green leaves and green pseudobulbs of Coelogyne rochussenii orchid and their responses to different growth irradiance and drought stress.
- Ameerah Sharainee Zain Binti Sha Aril Zain (2013) Accumulationandleaching of Cu, Zn and Cd and their effects on growth and photosynthesis in Epipremnum acureum plants.
- Aminda Chua (2011). The roles of photosynthetic pseudobulb of epiphytic C3 Oncidium in responses to short- and long-term drought and rewatering.
- Suriyati Mohamed Ali (2011). Response of Seagrasses to Water-Column Nutrient
- Lee Pei Sze (2011). Impact of Hydrilla verticillata and Najas indica on water quality of Lower Seletar Reservor.
- Cross Sharon Reena (2010). Lead uptake and effects on plant growth and photosynthesis of Piper sarmentosum (wild pepper) and Epipremnum acureum (money plants).
- Teo Wei Min Stephanie (2010) Photosynthetic characteristics and nitrogen metabolism of upper and lower pitchers of Nepenthes rafflesiana in responses to prey and inorganic nutrients.
- Hajjah Marlina Kumar (2009). The physiological role of pseudobulbs of Oncidium goldiana in orchid growth and development
- Zulaiha shireen (2009) Nitrogen metabolism and mineral Nutrition of carnivorous pitcher plants at different growth stages under greenhouse conditions.
- Lalitha d/o Jothinathan (2008). Effects of phosphate availability on physiological aspects of Chinese broccoli (Brassica alboglabra)