Physiological and biochemical plasticity of Lepidium latifolium as ‘sleeper weed’ in Western Himalayas

Abstract

To understand the spread of native populations of Lepidium latifolium growing in different altitudes in Ladakh region of Western Himalayas, photosynthetic and fluorescence characteristics were evaluated in relation to their micro-environment. Three sites representing sparsely populated (SPS), moderately populated (MPS) and densely populated site (DPS) were selected. Results showed that the DPS had higher photosynthetic accumulation than MPS and SPS. The higher transpiration rate at DPS despite lower vapor pressure deficit and higher relative humidity suggest the regulation of its leaf temperature by evaporative cooling. Intrinsic soil parameters such as water holding capacity and nutrient availability also play crucial role in higher biomass here. The quantum efficiency of PSII photochemistry (Fv/Fm, non-photochemical quenching (NPQ), ΦPSII) and light curve at various PPFDs suggests better light harvesting potential and light compensation point at DPS than the other two sites. Concomitantly, plants at SPS had significantly higher lipid peroxidation, suggesting a stressful environment, and higher induction of antioxidative enzymes. Metabolic content of reduced glutathione also suggests an efficient mechanism in DPS and MPS than SPS. High light intensities at MPS are managed by specialized contrive of carotenoid pigments and PsbS gene product. Large pool of violaxanthin and lutein plays an important role in this response. It is suggested that L. latifolium is present as 'sleeper weed' that has inherent biochemical plasticity involving multiple processes in Western Himalayas. Its potential spread is linked to site-specific micro-environment, whereby, it prefers flat valley bottoms with alluvial fills having high water availability, and has little or no altitudinal effect.

Current Challenges in Plant Eco-Metabolomics

“…In each of these processes, metabolite profiles can be used to measure plant responses with different biochemical resolution [ 112 ]. They can also be used to identify biochemical traits that can serve as marker, e.g., for phenotypic plasticity, chemical interactions with other organisms or resolving the invasive potential of exotic plants [ 37 , 47 , 110 ]. Thus, Eco-Metabolomics is a discipline which allows researchers to describe interactions between processes acting at different spatiotemporal scales.…”

Physiological, Biochemical and Reproductive Studies on Valeriana wallichii, a Critically Endangered Medicinal Plant of the Himalayan Region Grown under In-Situ and Ex-Situ Conditions

“…Chlorophyll fluorescence was measured on fully expanded leaves using a portable photosynthesis system (LI-6400, LI-COR, Lincoln, NE, USA) equipped with a fluorescence chamber (LI-6400-40) with modifications as in Bhat et al [29]. ΦPSII was determined as Fm -Fs/Fm , maximal efficiency of PSII by using Fv/Fm and intrinsic efficiency of PS II was by using Fv/Fm as suggested by Maxwell and Johnson [43].…”

“…Thus, proline metabolism may be considered as a key tool for protecting photosynthesis and increasing tolerance against stress conditions. Glutathione is known in signaling pathways that facilitate the acclimation of chloroplast processes to highlight and abiotic stress in order to increase yield and stress tolerance under changing environments [27][28][29][30]. Studies have shown that the detoxifying compounds such as reduced glutathione (GSH), proline and phenolics provide tolerance under changing environments [14,21,30,31].…”

Effect of temperature and insect herbivory on the regulation of glucosinolate‐myrosinase system in Lepidium latifolium

“…Lepidium latifolium (perennial pepperweed) is an ecologically important plant belonging to the family Brassicaceae. Although native to southern Europe and Asia (Bhat et al 2016, Schultze‐Motel 1986), it has shown widespread presence in most parts of the world, including the western United States, coastal New England, Mexico, Canada, and Australia (Young et al 1995). The wide ecological amplitude of Lepidium latifolium suggests that it is a reservoir of several novel physiological and biochemical mechanisms that help this plant to adapt to a diverse set of environmental conditions.…”

“…We have shown a responsive redox mechanism where the glutathione plays an important role in the induction of antioxidant enzymes having higher thiol content (Kaur, Bhat, et al 2013). Dynamic photosynthetic machinery to mitigate higher photosynthetic efficiency and light‐dependent xanthophyll cycle turnover has also been shown to suggest the wider adaptability of this plant in the Himalayas (Bhat et al 2016). Lepidium latifolium has also been recognized as the highest source of sinigrin having nutraceutical importance (Kaur, Hussain, et al 2013).…”