• Plant Adaptation Strategies
• Chemical Ecology
• Nutraceuticals

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. We have recently initiated work on Cannabis to understand regulation and environmental role of phyto-cannabinoids.

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). 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

Lepidium latifolium contains very high amount of glucosinolates particularly sinigrin that could be a reason for its abiotic and biotic adaptation. 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).

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). 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). 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.

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). 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.

(c) Development of Cannabis seeds as nutraceuticals.

• Understanding adaptive strategies in high altitude plants (CSIR, SERB)
• Elucidating the regulatory aspects of glucosinolate-myrosinase system in plants (CSIR, SERB)
• Understanding the physiological role of cannabinoids in plants (CSIR, Industry)
• Development of nutraceutical products from novel bioresources