Through its impact on morphogenesis, light is the key environmental factor that alters plant structural development; however, the understanding how light controls plant growth and developmental processes is still poor and needs further research. For this purpose, a Petri dish and pot experiment was conducted to investigate the effects of different LEDs, i.e., white light (WL), red light (RL), blue light (BL), and orange light (OL) on morphology, gas-exchange parameters, and antioxidant capacity of Brassica napus. Compared with WL, RL significantly promoted plant growth and biomass, contents of photosynthetic pigments, and gas-exchange parameters in comparison to BL and OL. However, RL also helped decline malondialdehyde and proline contents and superoxide anion and peroxide production rate. In contrast, BL and OL significantly reduced plant growth and biomass, gas-exchange attributes and increased the activities of superoxide dismutase and peroxidase in Petri dish as well as in pot experiment. These results suggest that red light could improve plant growth in B. napus plants through activating gas-exchange attributes, reduce reactive oxygen species accumulation, and promote antioxidant capacity.

Land use–land cover (LULC) alteration is primarily associated with land degradation, especially in recent decades, and has resulted in various harmful changes in the landscape. The normalized difference vegetation index (NDVI) has the prospective capacity to classify the vegetative characteristics of many ecological areas and has proven itself useful as a remote sensing (RS) tool in recording vegetative phenological aspects. Likewise, the normalized difference built-up index (NDBI) is used for quoting built-up areas. The current research objectives include identification of LULC, NDVI, and NDBI changes in Jhelum District, Punjab, Pakistan, during the last 30 years (1990–2020). This study targeted five major LULC classes: water channels, built-up area, barren land, forest, and cultivated land. Satellite imagery classification tools were used to identify LULC changes in Jhelum District, northern Punjab, Pakistan. The perception data about the environmental variations as conveyed by the 500 participants (mainly farmers) were also recorded and analyzed. The results depict that the majority of farmers (54%) believe in the appearance of more drastic changes such as less rainfall, drought, and decreased water availability for irrigation during 2020 compared to 30 years prior. Overall accuracy assessment of imagery classification was 83.2% and 88.8% for 1990, 88.1% and 85.7% for 2000, 86.5% and 86.7% for 2010, and 85.6% and 87.3% for 2020. The NDVI for Jhelum District was the highest in 1990 at +0.86 and the lowest in 2020 at +0.32; similarly, NDBI values were the highest in 2020 at +0.72 and the lowest in 1990 at −0.36. LULC change showed a clear association with temperature, NDBI, and NDVI in the study area. At the same time, variations in the land area of barren soil, vegetation, and built-up from 1990 to 2020 were quite prominent, possibly resulting in temperature increases, reduction in water for irrigation, and changing rainfall patterns. Farmers were found to be quite responsive to such climatic variations, diverting to framing possible mitigation approaches, but they need government assistance. The findings of this study, especially the causes and impacts of rapid LULC variations in the study area, need immediate attention from related government departments and policy makers.

No abstract

Use of Plantago ovata Forsk leaf (also known as blond plantain or isabgol) extract is a novel approach for ameliorating water stress in various agronomic crops such as maize (Zea mays L.). To examine the potential roles of P. ovata extract (0, 20 and 40%) in increasing seed germination, plant growth, photosynthetic measurements, stomatal properties, oxidative stress and antioxidant response, ions uptake and the relationship between studied parameters, we investigated the impacts of its short-term seed priming on Z. mays L. elite cultivar “Cimmyt-Pak” under a control environment and a water deficit stress environment (induced by PEG). It was evident that water deficit stress conditions induced a negative impact on plant growth, stomatal properties and ion uptake in different organs of Z. mays. The decrease in growth-related attributes might be due to overproduction of oxidative stress biomarkers, i.e., malondialdehyde (MDA) contents, hydrogen peroxide (H2O2) initiation, and electrolyte leakage (%), which was also overcome by the enzymatic antioxidants, i.e., superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) and non-enzymatic antioxidants, which increased under the water stress environment. However, seed priming with P. ovata extract positively increased germination rate and growth profile, and protected photosynthetic apparatus and stomatal properties by decreasing oxidative stress indicators and increasing activities of antioxidant compounds. Our results also depicted that the optimum concentration of P. ovata extract for Z. mays seedlings under water stress conditions was 20%, while a further increase in P. ovata extract (40%) induced a non-significant negative impact on growth and biomass of Z. mays seedling. In addition, the effect was more promising on Z. mays seedlings when grown under controlled conditions. Here, we concluded that the understanding of the role of seed priming with P. ovata extract in the increment of growth-related attributes, photosynthetic apparatus (Pn, Gs, Ts and Ci) and nutrient uptake (Ca2+, Fe2+, P and Mg2+) introduces new possibilities for their effective use in water deficit stress environments and shows a promising foundation for Z. mays tolerance against water deficit stress conditions.

Molybdenum (Mo), an essential microelement, may enhance the oxidative stress tolerance in plants. However, the efficacy of Mo might be variable with different forms of nitrogen (N) fertilizer. The present study was conducted to investigate the role of Mo application in regulating oxidative stress tolerance in winter wheat under different N sources. A hydroponic study was carried out comprising of two winter wheat cultivars '97003' and '97014' as Mo efficient and Mo inefficient, respectively, under two Mo levels (0 and 1 μM) and three different N sources (NO 3 , NH 4 NO 3 , or NH 4 +). Winter wheat plants supplied with different N sources accumulated superoxide anions (O 2 −), and malonaldehyde (MDA) contents in the order of NH 4 + > NO 3 > NH 4 NO 3 , suggesting that sole application of either N sources, especially sole NH 4 + source, may induce oxidative stress in winter wheat. However, Mo application decreased the MDA contents by 20.02%, 15.11%, and 25.89% in Mo-efficient cultivar and 30.75%, 23.79%, and 37.76% in Mo-inefficient cultivar under NO 3 , NH 4 NO 3 , and NH 4 + sources, respectively, while increased antioxidant enzyme activities and carotenoids and abscisic acid (ABA) contents up-regulated the expressions of TaAO and TaAba3 genes. Mo application regulated oxidative stress tolerance in winter wheat under different N sources through enhancing ABA production and ROS-scavenging enzymes. Mo-efficient '97003' winter wheat cultivar possesses a wider range of adaptability to withstand Mo-deficient conditions than Mo-inefficient '97014' cultivar.