Unlocking the mystery of plants’ survival capability under waterlogging stress

Waterlogging is a major abiotic stress affecting crop plants throughout the world, which hampers crop growth and causes yield loss. There are various types of responses in plants under this stress through the combined operation of different signaling and physiological pathways. However, the correlation between these pathways is extremely limited and not well described in the published papers. Therefore, the complex waterlogging stress-tolerance mechanisms need to be presented most coherently for a comprehensive understanding of this stress. Here, we present sequential responses in plants under oxygen-deprivation stress. The regulation of the N-end rule pathway may be treated as the initial signaling in plants after facing waterlogging stress, but still, it remains a controversial topic. All the pathways under waterlogging stress are directly or indirectly related to glycolysis, tricarboxylic acid (TCA) cycle, programmed cell death (PCD) and removal of reactive oxygen species (ROS). Scientists may consider alanine aminotransferase as the main controlling switch for surviving of plants under waterlogging stress. Triggering the genes responsible for alanine aminotransferase may act as a crucial one to develop a waterlogging tolerant plant due to its ability to control anaerobic fermentation, TCA cycle and efficient utilization of carbons

Mid storage seed hardening: a mechanical method to maintain seed viability during long term jute seed preservation

Seed plays an important role in agricultural sector for both production and consumption purpose. Availability of vigour seed is one of the major constraints for maximizing crop production. However, healthy seed can also lose its viability during seed storage by changing different physio-chemical properties. Influence of environmental factors and seed containers during storage leading to seed deterioration. In this research, mid storage seed hardening treatment was applied in different aged seeds of jute species (C. Capsularis & C. olitorius) with two types of storage bags. Seed hardening treatment showed the less moisture content with better germination percentage compared to the untreated species of jute seeds. Seed packing in polythene bags during both short and long term seed storages had higher viable seeds compared to the cloth packing seeds. The effect of seed hardening treatment on seed oil content and pattern of oil degradation is distinct in early period of storage. The faster rate of oil degradation, soluble protein and free amino acids was found in seeds of un-treated stored seeds in cloth bag. Contrary, very slow rate of oil degradation was observed in harden seed and stored in polythene bag which indicated better storability of harden seeds

Antioxidant properties of BJRI vegetable mesta-1 (Hibiscus sabdariffa L.)

Roselle or Mesta (Hibiscus sabdariffa) is one of the plants whose plant parts are used to prepare juices. The Roselle calyx is considered as a good source of antioxidants. But the antioxidant properties of BJRI (Bangladesh Jute Research Institute) released Roselle vegetable variety, BJRI vegetable mesta-1, is not quantified yet. With the objective of making this vegetable more popular among the consumers, an experiment was conducted at the Jute Agriculture Experimental Station, Bangladesh Jute Research Institute, Jagir, Manikganj to find out the antioxidant properties of BJRI vegetable mesta-1. Total four antioxidant components eg., total phenol content, total flavonoid content, proanthocyanidin content, anthocyanin content and three antioxidant activities eg., DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, (FRAP) ferric ion reducing antioxidant power, H2O2 (hydrogen peroxide), radical scavenging were measured from the calyx sample of BJRI vegetable mesta-1. Among the four antioxidant components, total flavonoid contents (959.53 mg 100 g–1) posses the highest position and anothocyanine contents (0.17 mg 100 g–1) were in the lowest position. FRAP activities were highest among the antioxidant activities of the calyx of our studied vegetable mesta. Our findings represented the quantity of antioxidant contents of the calyx of BJRI vegetable mesta-1 which justify its uses as natural antioxidants. Thus, Roselle calyx may act as an alternative source of antioxidant rich natural herbal tea

Phytohormone-Mediated Stomatal Response, Escape and Quiescence Strategies in Plants under Flooding Stress

Generally, flooding causes waterlogging or submergence stress which is considered as one of the most important abiotic factors that severely hinders plant growth and development. Plants might not complete their life cycle even in short duration of flooding. As biologically intelligent organisms, plants always try to resist or survive under such adverse circumstances by adapting a wide array of mechanisms including hormonal homeostasis. Under this mechanism, plants try to adapt through diverse morphological, physiological and molecular changes, including the closing of stomata, elongating of petioles, hollow stems or internodes, or maintaining minimum physiological activity to store energy to combat post-flooding stress and to continue normal growth and development. Mainly, ethylene, gibberellins (GA) and abscisic acid (ABA) are directly and/or indirectly involved in hormonal homeostasis mechanisms. Responses of specific genes or transcription factors or reactive oxygen species (ROS) maintain the equilibrium between stomatal opening and closing, which is one of the fastest responses in plants when encountering flooding stress conditions. In this review paper, the sequential steps of some of the hormone-dependent survival mechanisms of plants under flooding stress conditions have been critically discussed