Dr. Dhiraj Vyas

Plant Science Division
CSIR - Indian Institute of Integrative Medicine,Canal Road, Jammu – 180001
Email: dvyas[at]iiim[dot]ac[dot]in, dhirajvyas[at]rediffmail[dot]com

Positions Held  
Position Held Date Organization
Principal Scientist 2016 - till date CSIR-IIIM
Senior Scientist 2012 - 2016 CSIR-IIIM
Scientist 2008 - 2012 CSIR-IIIM
Lecturer 2005 - 2008 Shri Mata Vaishno Devi University, Katra
Research Scientist 2005 - 2005 Dabur Research Foundation, Gaziabaad
Research Associate 2004 - 2005 National Institute for Plant Biotechnology, New Delhi
Honours & Awards  
  • BOYSCAST Fellow

  • Fellow, Indian Society of Plant Biochemists

  • Academic Excellence Award CSIR-IHBT

  • Honor’s Certificate in M.Sc.

Research Area

We are interested to understand plant biology as a whole to decipher intricate PLANT-ENVIRONMENT interactions. Our approach is to use physiological, biochemical and molecular means to understand these relationship. We utilize all techniques to reach to the core of the question. We have selected Lepidium latifolium as a system to prove various hypothesis. Sometimes, we take advantage of model plant Arabidopsis thaliana and its mutants to reach to a conclusion.

(Overall Research Areas and the Crux)

Plant source

Flowering Lepidium latifolium in its native environment in Ladakh

Lepidium latifolium L. (perennial pepperweed) is a plant of family Brassicaceae that has now attracted attention of ecologists after being recognized as noxious weed along the West coast of North America (Young et al. 1995). It is native to southern Europe and Asia (Hulte´n and Fries 1986) and is widespread in most parts of the world including Western United States, coastal New England, Mexico, Canada and Australia (Young et al. 1995). Properties that have contributed to its establishment include prolific seed production, rapid and substantial vegetative growth, creeping rhizomes with high storage capacity, potential for bud formation at each node, and deep rhizome penetration (Francis and Warwick 2007). It can tolerate shade, sun, and extensive flooding, but likes to establish near wetlands, riverbanks, riparian areas and flood plains (Renz et al. 2004). In India, L. latifolium is found in the cold-arid zone of Ladakh Himalayas where it grows naturally at altitudes ranging from 2500 m to 4500 m above sea level in parts of Jammu and Kashmir and Himachal Pradesh, and it is used as phytofood (Kaur et al. 2013). Owing to its adaptive potential, many genes have recently been isolated from this plant. Barring a few locations, the growth of L. latifolium in Ladakh is generally restricted to sporadic patches and does not show prolific growth. However, as established in riparian plains of Western America, this species has the potential for invasive growth under changed resource environment.

Role of Glucosinolates in Plant-Environment Interactions
Glucosinolate-myrosinase (GLS-MYR) system is an important component of plant-insect interactions in family Brassicaceae. GLS-MYR is an enzyme-substrate complex that is physically separated in different cells. GLSs are N and S containing glycosides sharing a same basic structure where a β-thioglucose is linked by a sulfur atom to a (Z)-N-hydroximinosulfate ester, and a variable side chain derived from amino acids (Halkier and Gershenzon, 2006). Upon tissue damage (physical/herbivory), GLSs are decomposed by MYR into several hydrolysis products including isothiocyanates, thiocyanates, simple nitriles, and epithionitriles that are responsible for producing complex biological effects mainly during insect interactions. The diversity of products is a result of differential chemical nature of the GLSs and the hydrolysis conditions (Bhat and Vyas, 2019). Thiohydroximate-O-sulfate generated during hydrolysis of GLSs by MYR gets converted to isothiocyanate by a spontaneous arrangement under neutral pH or to nitriles at low pH values (< 5) or in the presence of high ferrous ion concentrations (> 0.01 mM). Nitrile production is also promoted from all GLSs in the presence of the nitrile-specifier protein (NSP) or from the GLSs lacking terminal double bond in the side chain by epithionitrile protein (ESP) at physiological pH values.

Apart from their proven role in insect interactions, glucosinolates and their hydrolysis products have also shown to play role in the abiotic stress tolerance. During salt stress, sinigrin was shown to regulate aquaporins and water transport, showing the ability of the roots to promote cellular water transport across the plasma membrane (Mart´ınez-Ballesta et al., 2014). Allyl isothiocyanate, the hydrolysis product of sinigrin, induced stomatal closure in Arabidopsis via production of reactive oxygen species (ROS) and nitric oxide (NO), and elevation of cytosolic Ca2+ (Khokhan et al., 2011). AITC has also shown to reduce the metabolic content of glutathione in Arabiopsis (Oliver et al., 2015) suggesting changed redox environment.

Keeping these fundamentals in view, our lab is interested in:
(a) Profiling of glucosinolates and their hydrolysis products in Lepidium latifolium and their role in insect-interactions.
(b) Understanding the role of redox regulations in qualitative and quantitative outcome of glucosinolates and their hydrolysis products.
(c) Bio-prospection of enzymes and genes related to glucosinolate-myrosinase system from Lepidium latifolium.
(d) Role of sinigrin and its hydrolysis products in abiotic stress tolerance with special reference of Ladakh.

Eco-physiology and Plant Adaptation Strategies
The hypothesis that climate varies future patterns of plant biodiversity is now well established (Dawson et al. 2011) and it is predicted that this could become greatest global threat to biodiversity over the next few decades (Pereira et al. 2010). Asian highlands, including that of the Himalayas have considerable global importance in a climate change scenario as this ‘Water Tower of Asia’ directly sustains approximately 150 million people and has impacted on the lives of several billion downstream dwellers (Xu et al. 2009). Himalayas has been found more sensitive to global climate change as progressive increases in warming is already occurring at approximately 2-3 times the global average (Salinger et al. 2014). This would lead to variable precipitation trends (Salick et al. 2014), and impacts at multiple scales from species to ecosystems have been observed.  Changes in hydrology can influence biodiversity by changing moisture availability that governs physiology, metabolic and reproductive processes, phenology, tree-line positions, and the geographic distribution of freshwater and wetland habitats.
During climate change, the native species may be out-competed by faster growing, more plastic and aggressive species extending their range (Walther et al. 2009) or there is a possibility of changing growth and habitat patterns of native species under resource changed environment (Ranjitkar et al. 2013). For decades, understanding phenotypic plasticity of any plant has been instrumental in determining its recruitment/spread over a geographical area (Funk and Vitousek 2007). The traits that were mainly considered include morphological differentiation in terms of size, growth rate, shoot allocation, leaf area allocation, etc. However, there has been increased focus on physiological and biochemical plasticity in recruitment of any plant species (Pinto-Marijuan and Munne-Bosch 2013, Davidson et al. 2011). There have been conflicting reports on the role of performance related trait plasticity in plant invasiveness and adaptation, wherein, a few studies support greater values/plasticity as a measure (Kleunen et al. 2010, Funk and Vitousek 2007) while others do not suggest any advantage (Leishman et al. 2010, Davidson et al.2011, Palaci-Lopez and Gianoli 2011, Matzek 2012) in normal as well as a resource limiting environments. Hence, it may be presumed that phenotypic plasticity is a species specific trait which, may or may not end up in its invasive/adaptive advantage.
Ladakh Himalayas have been ecologically one of the most fragile region of the world. Stressful conditions in this region is characterized by large temperature variations, sub zero temperatures, low annual precipitation (100–300 mm mostly in form of snow), intense radiation load, varying moisture levels, nutrient-poor substrates and low partial pressure of gases (Kaur et al., 2016). The changes in temperature and moisture governs physiology, metabolic and reproductive processes, phenology, growth and productivity, leading to the distribution shifts (Chen et al., 2011) and changes in plant cover (Parmesan and Yohe, 2003), hence, influencing ecological distribution (Barral, 2019; Chen et al., 2017; M€unzbergova et al., 2017; Dolezal et al., 2016). It is predicted that while the global mean air temperature increases of another 1 - 3.7 °C by the end of century, the high latitudes could warm by 10 °C (Ciais et al., 2013). Along with the threat of mean rise in temperature, the Ladakh Himalayas have also shown very high variability where the temperature may vary from 34.8 °C in summers, dropping to as low as −27.9 °C in winters (Chevuturi et al., 2018). These fluctuations along with diurnal asymmetry have shown large impact on photosynthetic machinery and requires plants to have dynamic regulation of absorbed light energy with the energy consumed by various metabolic pathways (Dusenge et al., 2018).
Therefore, there is urgent need to prioritize the plant biodiversity in an extremely important strategic region of Ladakh. For achieving this, we need to understand the adaptive mechanisms and mitigation strategies of plants growing in that environment. Lepidium latifolium is an important plant to help achieve this understanding as it has wide ecological amplitude in Ladakh region. Our interest lies in:
(a) To understand plant biodiversity changes in the long term ecological research plots in Ladakh.
(b) To associate physiological and biochemical changes vis-a-vis climate change in order to predict future spread.
(c) To understand temperature and light mitigation strategies in extreme environments.

Glucosinolate based Nutraceuticals
Family brassicaceae comprise many economically important species distributed worldwide and utilized traditionally for culinary and medicinal purposes. Their functional properties are due to their phytochemical composition, mainly consisting of specialized glucosinolates (GLS) and their hydrolysis products (Fusari et al., 2020). Various laboratory and epidemiological studies have associated these with biological activities, including significantly lower risk of myocardial infarction and cancer development at different sites, anti-inflammatory, immunomodulatory activities, antimicrobial, restoration of skin integrity, and protection of central nervous system (Traka, 2016). The mechanisms of bioactivity of GLSs include regulation of xenobiotic metabolism, reduction of inflammation, regulation of epigenetic events, apoptosis and cell cycle arrest, angiogenesis and metastasis, antibacterial effect, induction of glyoxalase 1 activity, and modulation of hormone receptor expression (Capuano et al., 2017). GLS are part of the human diet as vegetables (cabbage, broccoli, cauliflower, Lepidium, etc.), root vegetables (e.g., radish, turnip, swede, etc.), leafy vegetables (rocket salad, etc.), seasonings and relishes (mustard, wasabi, etc.) and sources of oil (Verkerk et al., 2009).
Lepidium latifolium L. is used as phytofood by the native population of Ladakh, and shows a very high (90-95%) content of 2-propenyl GLS (sinigrin) in its leaves (Kaur et al., 2013). It also contains a significant amount of phenols, flavonoids, fatty acids, and has efficient antioxidant potential. Apart from edible purposes, it has also been reported to have therapeutic properties as a diuretic, antihypertensive, and anti-tumour (Conde-Rioll et al., 2018). Therefore, a viable, functional food derived from Lepidium latifolium is desirable to utilize its unique properties. Therefore our aim is:

(a) Utilization of Lepidium latifolium as a functional food.

(b) Bio-fortification of glucosinolates and other nutraceutically important metabolites.

(c) Use of metabolomic approach in nutraceutical development. 

Cannabis Research
Cannabis belonging to family Cannabaceae is an important plant since times immemorial. It is thought to be originated in central Asia (Li, 1973), and is a source of durable fibers, nutritious seeds, and psychoactive metabolites. Recently after legalization in several countries, many efforts have started to understand its biology and medicinal potential. Although, Cannabis contains over 200 secondary metabolites, including terpenes, and phenolic acids (Andre et al., 2016), the medicinal properties are mainly credited to cannabinoids, containing alkyl resorcinol and monoterpene moieties in their molecules. More than 90 cannabinoids have been isolated from Cannabis sativa till date, which includes mainly ∆9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene, cannabinolic acid, cannabigerolic acid, cannabichromenic acid, cannabinodiolic acid, and tetrahydrocannabivarin (El Sohly and Slade, 2005; Booth and Bohlmann, 2019). Most of the medicinal and pharmacological activities have been studied on psychoactive cannabinoid, THC, and recently from non-psychoactive cannabinoid, CBD, leading to the introduction of first FDA approved Cannabis-derived drug for severe epilepsy (Mullard, 2018). The important consideration of the cannabis industry is therefore, the yield of cannabinoids and their profile, which together determine the quality of the product. Apart from the genetic structure (Sawler et al., 2015; Welling et al., 2016) and chemotaxonomy (Hazekamp et al., 2004), other environmental factors such as microbial inoculants, the role of light intensity and photoperiod, temperature, fertilization, physiological stresses, plant density and elicitors have shown effects on the quantitative and qualitative cannabinoid yield and profile (Becker et al., 2019).

Our objectives in the Cannabis research lies in:
(a) Understanding the regulatory aspects of Cannabinoid biosynthesis.

(b) Role of Cannabinoids in adaptation of Cannabis.  

Publications

From Core Work of Lab

  • Manu Khajuria, VP Rahul and Dhiraj Vyas* (2020) Zeaxanthin-dependent non-photochemical quenching is negatively correlated with the ∆9-tetrahydrocannabinol content in Cannabis sativa L. Plant Physiology and Biochemistry 151: 589–600.

  • Rajat Mohan, Tarandeep Kaur, Hilal A. Bhat, Manu Khajuria, Sikander Pal and  Dhiraj Vyas* (2019) Paclobutrazol Induces Photochemical Efficiency in Mulberry (Morus alba L.) Under Water Stress and Affects Leaf Yield Without Influencing Biotic Interactions. Journal of Plant Growth Regulation 39: 205–215.

  • Rohini Bhat and Dhiraj Vyas* (2019) Myrosinase: insights on structural, catalytic, regulatory, and environmental interactions. Critical Reviews in Biotechnology 39(4): 508-523.

  • Tarandeep Kaur, Rohini Bhat, Manu Khajuria, Ruchika Vyas, Anika Kumari, Gireesh Nadda, Ram Vishwakarma and Dhiraj Vyas* (2016) Dynamics of glucosinolate-myrosinase system during Plutella xylostella interaction to a novel host Lepidium latifolium L. Plant Science 250: 1–9.

  • Hilal Bhat, Tarandeep Kaur, Rohini Bhat and Dhiraj Vyas* (2016) Physiological and biochemical plasticity of Lepidium latifolium L. as ‘sleeper weed’ in Western Himalayas. Physiologia Plantarum 156: 278–293.

  • Tarandeep Kaur, Rohini Bhat and Dhiraj Vyas* (2016) Effect of contrasting climates on antioxidant and bioactive constituents in five medicinal herbs in western Himalayas. Journal of Mountain Science 13: 44-492.

  • Rohini Bhat, Tarandeep Kaur, Manu Khajuria, Ruchika Vyas and Dhiraj Vyas* (2015) Purification and Characterization of a Novel Redox Regulated Isoform of Myrosinase (β-thioglucoside glucohydrolase) from Lepidium latifolium L. Journal of Agricultural and Food Chemistry 63: 10218−10226.

  • Tarandeep Kaur, Hilal A. Bhat, Rohini Bhat, Arun Kumar, Kushal Bindu, Sushma Koul and Dhiraj Vyas* (2015) Physio-chemical and antioxidant profiling of Salvia sclarea L. at different climates in north-western Himalayas. Acta Physiologiae Plantarum 37: 132.

  • Tarandeep Kaur, Khadim Hussain, Sushma Koul, Ram Vishwakarma, Dhiraj Vyas* (2013) Evaluation of Nutritional and Antioxidant Status of Lepidium latifolium Linn.: A Novel Phytofood from Ladakh. PLoS ONE 8(8): e69112.

  • Tarandeep Kaur, Hilal A. Bhat, Anuj Raina, Sushma Koul, Dhiraj Vyas* (2013) Glutathione regulates enzymatic antioxidant defence with differential thiol content in perennial pepperweed and helps adapting to extreme environment. Acta Physiologiae Plantarum 35:2501–2511.

  • Arun Kumar, Esha Abrol, Sushma Koul, Dhiraj Vyas* (2012) Seasonal low temperature plays an important role in increasing metabolic content of secondary metabolites in Withania somnifera (L.) Dunal and affects the time of harvesting. Acta Physiologiae Plantarum 34:2027–2031.

  • Esha Abrol, Dhiraj Vyas*, Sushma Koul (2012) Metabolic shift from secondary metabolite production to induction of anti-oxidative enzymes during NaCl stress in Swertia chirata Buch.-Ham. Acta Physiologiae Plantarum 34:541–546.

  • Dhiraj Vyas*, Sanjay Kumar and Paramvir Singh Ahuja (2007) Tea (Camellia sinensis) clones with shorter periods of winter dormancy exhibit lower accumulation of reactive oxygen species. Tree Physiology 27: 1253-1259.

  • Narinder Kumar, Dhiraj Vyas and Sanjay Kumar (2007) Plants at high altitude exhibit higher component of alternative respiration. Journal of Plant Physiology 164(1):31-38.

  • Shweta Sood, Dhiraj Vyas and Pramod Kumar Nagar (2006) Physiological and Biochemical Studies during Flower Development in Two Rose Species. Scientia Horticulturae 108: 390-396.

  • Dhiraj Vyas* and Sanjay Kumar (2005) Purification and partial characterization of a low temperature responsive Mn-SOD from tea (Camellia sinensis (L.) O. Kuntze). Biochemical and Biophysical Research Communications 329: 831-838.

  • Dhiraj Vyas* and Sanjay Kumar (2005) Tea (Camellia sinensis (L.) O. Kuntze) clone with lower period of winter dormancy exhibits lesser cellular damage in response to low temperature. Plant Physiology and Biochemistry 43: 383-388.

  • Dhiraj Vyas*, SK Sharma and DR Sharma (2003) Genetic structure of walnut genotype in India using leaf isozymes as variability measure. Scientia Horticulturae 97(2): 141-152.

  • Dhiraj Vyas, Rasmita Sahoo and Sanjay Kumar (2002) Possible mechanism and implication of phenolics mediated reduction of XTT. Current Science 83(12): 1588-1592.

Current Members

Ms Manu Khajuria
M.Sc. Botany
(DST-INSPIRE SRF)

Topic of Research

  • Photosynthetic adaptations of Lepidium latifolium L. in trans-Himalayan regions of Ladakh Area.
  • Structural biology of the photosynthetic system.

Mr Villayat Ali
M.Sc. Botany
(CSIR-SRF)

Topic of Research

  • Biofortification and regulation of  glucosinolates in Lepidium latifolium  sprouts.
  • Regulation of sulfur in primary and secondary metabolism.

Mr Aatif Rashid
M.Sc. Biotechnology
(SRF)

Topic of Research

  • Understanding nutraceutical potential of Cannabis seeds.
  • Understanding the regulation of cannabinoid biosynthesis and regulation mediated through plant hormones.

Ms Sheenam Faiz
M.Sc. Botany
(DST-INSPIRE SRF)

Topic of Research

  • Profiling and regulation of glucosinolate hydrolysis products in Lepidium latifolium.
  • Role of allyl thiocyante in environmental interactions of Lepidium latifolium L.

Mr Sumit Jamwal
M.Sc. Biochemistry
(JRF)

Topic of Research

  • Understand the effect of Cannabinoids in the photosynthetic  adaptations in plants.
  • Regulation of abiotic stress regulatory proteins.


Past Members

Dr Tarandeep Kaur
PhD Biological Science
Presently working as Senior Manager, Tissue culture, molecular testing and minitubers facility Bhatti Tissue Tech., Jalandhar, Punjab

Topic of Research

  • Evaluating the Role of Glutathione Mediated Redox Homeostasis vis à vis Glucosinolate

Dr Rohini Bhat
PhD Biological Science
Presently, Post Doc Fellow at National Center For Biological Sciences, Bengaluru-India.

Topic of Research

  • Biochemical and Molecular Characterization of Glucosinolate-Myrosinase System from Lepidium latifolium L.

Facilities

Our lab uses all physiological, biochemical and molecular techniques to unravel the queries of science. We regularly use Infra Red Gas Analyser, Fluorescence Meter, HPLC, Western Analysis, Quantitative PCR, 2-D Electrophoresis, Microscopy, Growth Chambers, etc along with other commonly used instruments in the lab.