Response of photosynthetic apparatus in some sunflower cultivars, i.e., S.28111, Hysun-33, Hysun-39, and SF0049, to salt, drought, and combined stresses were studied. The combined stress caused severe damage to photosynthetic apparatus as compared to single stress. The maximum quantum yield of PSII, phenomenological fluxes, plastoquinone pool size, performance indexes, and driving force of absorption were greatly affected by the combined stress. Among the cultivars, the combined stress produced synergistic effect (greater damage) in Hysun-33 and cross-tolerance (lesser damage) in S.28111. Similarly, concerning the ion imbalance, S.28111 and SF0049 showed lower Na + and Clconcentrations with lesser electrolyte leakage as compared to Hysun-33 and Hysun-39 under salt and combined stress. Results revealed that the disturbance in photosynthetic performance could be easily determined using JIP test by measuring chlorophyll a fluorescence. This information can be useful for the screening of oil-seed crop plants having better photosynthetic performance under salinized and desertified conditions.Additional key words: electron transport rate; malondialdehyde; nonphotochemical quenching; OJIP transient. Abbreviations: ABS/RC -apparent antenna size of active PSII RC; Area -area over the fluorescence curve between F0 and Fm; DFABSdriving force on absorption basis; DI0/RC -effective dissipation of energy in active RC; ET0/RC -electron transport per active reaction center; F0 -minimum fluorescence; F0/Fv -efficiency of water-splitting complex; F0/Fm -quantum yield baseline; Fm -maximum fluorescence; Fm/F0 -electron transport rate through PSII; Fv/F0 -size and number of active reaction centers of photosynthetic apparatus; Fv/Fm -maximum quantum yield of PSII; J -linear electron transport rate; MDA -malondialdehyde; NPQ -nonphotochemical quenching; PIABS -performance index on absorption basis; PICS -performance index on cross-section basis; PItot -total performance index; qN -nonphotochemical quenching coefficient; qP -photochemical quenching; RC/ABS -density of reaction centers on chlorophyll basis; RC/CSm -amount of active reaction centers per excited cross section; TR0/DI0 -ratio of trapping and dissipation fluxes; TR0/RC -maximal trapping rate of absorbed photons in RC; δR0 or RE0/ET0 -probability that an electron is transported from reduced PQ to electron acceptor side of PSI; ΔVIP -amplitude of the relative variable fluorescence of the I-to-P-rise; ΦPSII -efficiency of PSII or quantum yield of PSII; ϕR0 -quantum yield for reduction of the end electron acceptors at the PSI acceptor side (RE); ψ0yield of electron transport per trapped excitation or probability with which a PSII trapped electron is transferred from reduced QA to QB.

The physiological performance of some sunflower genotypes (S.28111, SF0049, Hysun-33, Hysun-39) under salt, drought stress separately and in combination was examined. Salt, drought and a combination of these stresses were applied to plants by gradual increments. The plants were exposed to stress for two weeks. Relative water content, osmotic potential, stomatal conductance, performance index, dark adapted quantum yield and chlorophyll contents were reduced upon salinity and drought stresses. However, when plants were subjected to a combination of these stresses, a greater reduction in all tested attributes was observed. Proline and carotenoid contents in drought stress were elevated compared to salt stress. Superoxide dismutase (SOD) and catalase (CAT) showed the highest activity in individual salt and drought stress with less accumulation of H2O2. Combined stress reduced the activity of antioxidant enzymes which ultimately decreased the physiological performance of sunflower plants. However, among the tested genotypes, S.28111 and SF0049 were found to be more tolerant to drought, salt and combined stress than both Hysun genotypes. The physiological performance of genotypes against salinity and drought individually and in combination is discussed in detail.

The present study aimed to witness the plant–microbe interaction associated with salt tolerance in crops. We isolated the endophytic microbe from the root zone of halophytic grass. Later, the salt tolerance of the endophyte was tested in the saline medium and was identified using nucleotide sequencing (GenBank under the accession numbers: SUB9030920AH1_AHK_ITS1MW570850: SUB9030920AH1_AHK_ITS4MW570851). Rice and maize seeds were coated with identified endophyte Aspergillus terreus and were sown in separate plastic pots. Later 21-day-old seedlings were subjected to three NaCl concentrations, including 50, 100, and 150 mM salt stress. Under saline conditions, A. terreus showed a substantial increase in growth, biomass, relative water content, oxidative balance, and photochemical efficiency of rice and maize plants. The data reflected that the stimulation of gibberellic acid (GA) in treated leaves may be the main reason for the upregulation of photosynthesis and the antioxidant defense cascade. The data also depict the downregulation of oxidative damage markers malondialdehyde, hydrogen peroxide in rice and maize plants. Conclusively, salt-tolerant endophytic fungus A. terreus explicitly displayed the positive plant–microbe interaction by developing salt tolerance in rice and maize plants. Salt tolerance by endophytic fungus coincides with the enhanced GA concentration, which illustrated the stimulated physiological mechanism and gene in response to the extreme environmental crisis, resulting in improved crop productivity.

prolific habitat for water birds arriving from the Siberia (The Dawn, 2016). Pakistan is included in the list of countries which harbor > 400 of migratory birds (UNEP, 2014) annually that take an exhaustive and perilous journey of about 4500 km. The itinerary of these birds that lasts for 4-5 months in Pakistan is facilitated by wetlands and Ramsar sites located along the Indus basin providing them habitat and food requirements. These birds enter into Pakistan from September-November via Indus flyway over the Karakorum and the Suleiman mountain ranges then entering to the delta of Indus River near the Arabian Sea and stay till February -March and finally returning to their breeding habitats (Sheikh and Kashif, 2006).

The Vaccinium genus comprises more than 126 genera of perennial flowering plants that are commonly adapted to poor and acidic soils or epiphytic environments. Their molecular and genomic characterization is a result of the recent advent in next-generation sequencing technology. In the current research, extracts were prepared in different media, such as petroleum ether, methanol and ethanol. An extract of Vaccinium macrocarpon (cranberry) was used at a dose of 200-400 mg/kg by weight (B.wt). Levels of oxidative stress markers, i.e., superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), advanced oxidation protein products (AOPPs) and malondialdehyde (MDA), were measured. A histopathological study of six vital organs in rats was also conducted. The results indicated that the antioxidant levels were lower in the group given only ethylene oxide (EtO) but higher in the groups receiving cranberry extract as a treatment. Major improvements were also observed in stress markers such as advanced oxidation protein products (AOPPs) and MDA following cranberry treatment. Histopathological changes induced by EtO were observed in the heart, kidney, liver, lung, stomach and testis and were reversed following cranberry treatment. The major toxic effects of EtO were oxidative stress and organ degeneration, as observed from various stress markers and histopathological changes. Our study showed that this extract contains strong antioxidant properties, which may contribute to the amelioration of the observed toxic effects.