Seed priming is a simple, inexpensive, and effective pre-sowing technique that enables plants to better tolerate abiotic stresses, including high soil salinity, which is a major limiting factor in the establishment of halophytes for saline agriculture, as germinating seeds and early seedlings of many halophytes are sensitive compared to the mature vegetative stage. This article attempts to provide an overview of the research on the seed priming effects on halophyte seeds and subsequent seedlings/plants. Different physio-chemical and molecular processes, including the induction of priming/stress memory, which enhance salinity tolerance following seed priming, have also been discussed. This review also covers the aspects of reactive oxygen species (ROS), and nitric oxide (NO) signaling(s) that are activated as a result of seed priming. Finally, the limitations and prospects of seed priming to enhance the agronomic potential of halophytes for saline agriculture have been discussed.

Halophytes are naturally salt-tolerant plants with immense potential to become alternate crops for saline lands. While their economic benefits have gained increasing attention, often, the roles of halophytes in addressing different climate change-related issues are overlooked. Halophytes can be a renewable resource for clean ‘carbon-neutral’ energy by serving as biofuel or biogas feedstock, help in the sequestration of rising CO₂ as well as the phytoremediation of various pollutants, can be a good source of food and fodder thereby help in achieving food security in arid/saline areas, can help in protection and biodiversity conservation in various ecosystems, and can provide livelihood to poor local communities inhabiting barren lands. This review also attempts to highlight various usages of halophytes in connection with a global change perspective. However, there are still many challenges such as economic viability, customer preferences, environmental impacts, and scale-up challenges, which need further research, innovation, effective policies, and collaboration. In general, this review provides a synthesis of various biological, environmental, and socioeconomic aspects of halophytes to fully exploit the potential of halophytes for human welfare and combating global climate changes.

Plant photosynthesis and biomass production are closely associated traits but critical to unfavorable environmental constraints such as salinity and drought. The relationships among stress tolerance, photosynthetic mechanisms, biomass and ethanol yield were assessed in Phragmites karka. The growth parameters, leaf gas exchange and chlorophyll fluorescence of P. karka were studied when irrigated with the control and 100 and 300 mM NaCl in a nutrient solution and water deficit conditions (drought, at 50% water holding capacity). The plant shoot fresh biomass was increased in the low NaCl concentration; however, it significantly declined in high salinity and drought. Interestingly the addition of low salinity increased the shoot biomass and ethanol yield. The number of tillers was increased at 100 mM NaCl in comparison to the control treatment. High salinity increased the photosynthetic performance, but there were no significant changes in drought-treated plants. The saturated irradiance (Is) for photosynthesis increased significantly in low salinity, but it declined (about 50%) in high salt-stressed and (about 20%) in drought-treated plants compared to the control. The rates of dark respiration (Rd) and compensation irradiance (Ic) were decreased significantly under all treatments of salinity and drought, with the exception of unchanged Rd values in the control and drought treatments. A-Ci curve analyses revealed a significant improvement in the Jmax, Vc, max, and triose-phosphate utilization (TPU) at lower salinity levels but decreased at 300 mM NaCl and drought treatments compared to the control. In the chlorophyll fluorescence parameters (Fv/Fm, maximum photochemical quantum yield of PSII, and Y(NO)), the non-photochemical yields were not affected under the salt and drought treatments, although an effective photochemical quantum yield (YII) and electron transport rate (ETR) were significantly enhanced in water deficit compared to control plants. P. karka regulates an efficient photosynthesis mechanism to grow in saline and arid areas and can therefore be used as a sustainable biofuel crop.

Seed heteromorphism is the production of two or more types of seeds by a single individual of many plant species. On the basis of an extensive...