Mirza Hasanuzzaman

By Mirza Hasanuzzaman, Kamrun Nahar and Masayuki Fujita

Part of the book: Abiotic Stress

By Anisur Rahman, Kamrun Nahar, Jubayer Al Mahmud, Mirza Hasanuzzaman, Md. Shahadat Hossain and Masayuki Fujita

Excess salinity in soil is one of the major environmental factors that limit plant growth and yield of a wide variety of crops including rice. On the basis of tolerance ability toward salinity, rice is considered as salt-sensitive crop, and growth and yield of rice are greatly affected by salinity. In general, rice can tolerate a small amount of saltwater without compromising the growth and yield. However, it greatly depends on the types and species of rice and their growth stage. Salinity-induced ionic and osmotic stresses reduce rate of photosynthesis and consequently cause oxidative stress, which is also responsible for growth reduction. The negative effects of salt stress that mentioned ultimately reduced yield of most crops including rice, except some halophytes. In recent decades, researchers have developed various approaches toward making salt-tolerant rice varieties. Using phytoprotectants is found to be effective in conferring salt tolerance to rice plants. In this chapter, we reviewed the recent reports on different aspects on salt stress tolerance strategies in light of using phytoprotectants.

Part of the book: Advances in International Rice Research

By Mirza Hasanuzzaman, Kamrun Nahar, Anisur Rahman, Taufika Islam Anee, Mazhar Ul Alam, Tasnim Farha Bhuiyan, Hirosuke Oku and Masayuki Fujita

Wheat is consumed as a staple food by more than 36% of world population. Wheat provides nearly 55% of the carbohydrates and 20% of the food calories consumed globally. The productivity of wheat is often adversely affected by salt stress which is associated with decreased germination percentage, reduced growth, altered reproductive behavior, altered enzymatic activity, disrupted photosynthesis, damage of ultrastructure of cellular components, hormonal imbalance, and oxidative stress. Different approaches have been adopted to improve plant performance under salt stress: introduction of genes, screening of better performing genotypes, and crop improvement through conventional breeding methods which are often not so successful and suitable due to time-consuming or reduction of plant vigor with the succession of time. Uses of exogenous phytoprotectants, seed priming, nutrient management, and application of plant hormone are convenient for improving plant performances. This chapter reviews the mechanism of damage of wheat plants under salt stress and also the recent approaches to improve growth and productivity of salt-affected wheat plants emphasizing the use of exogenous phytoprotectants from the available literature.

Part of the book: Wheat Improvement, Management and Utilization

By Mirza Hasanuzzaman, Kamrun Nahar, Tasnim Farha Bhuiyan, Taufika Islam Anee, Masashi Inafuku, Hirosuke Oku and Masayuki Fujita

Salicylic acid (SA) is an endogenous growth regulator of phenolic nature and also a signaling molecule, which participates in the regulation of physiological processes in plants such as growth, photosynthesis, and other metabolic processes. Several studies support a major role of SA in modulating the plant response to various abiotic stresses. It is a well-founded fact that SA potentially generates a wide array of metabolic responses in plants and also affects plant-water relations. This molecule also found to be very active in mitigating oxidative stress under adverse environmental conditions. Since abiotic stress remained the greatest constraints for crop production worldwide, finding effective approaches is an important task for plant biologists. Hence, understanding the physiological role of SA would help in developing abiotic stress tolerance in plants. In this chapter, we will shed light on the recent progress on the regulatory role of SA in mitigating abiotic stress.

Part of the book: Phytohormones

By Mirza Hasanuzzaman, Khursheda Parvin, Taufika Islam Anee, Abdul Awal Chowdhury Masud and Farzana Nowroz

Soybean is one of the major oil crops with multiple uses which is gaining popularity worldwide. Apart from the edible oil, this crop provides various food materials for humans as well as feeds and fodder for animals. Although soybean is suitable for a wide range of soils and climates, it is sensitive to different abiotic stress such as salinity, drought, metal/metalloid toxicity, and extreme temperatures. Among them, soil salinity is one of the major threats to soybean production and the higher yield of soybean is often limited by salt stress. Salt stress negatively affects soybean seedling establishment, growth, physiology, metabolism, and the ultimate yield and quality of crops. At cellular level, salt stress results in the excess generation of reactive oxygen species and creates oxidative stress. However, these responses are greatly varied among the genotypes. Therefore, finding the precise plant responses and appropriate adaptive features is very important to develop salt tolerant soybean varieties. In this connection, researchers have reported many physiological, molecular, and agronomic approaches in enhancing salt tolerance in soybean. However, these endeavors are still in the primary stage and need to be fine-tuned. In this chapter, we summarized the recent reports on the soybean responses to salt stress and the different mechanisms to confer stress tolerance.

Part of the book: Plant Stress Physiology

By Md. Rakib Hossain Raihan, Kamrun Nahar, Farzana Nowroz, Ayesha Siddika and Mirza Hasanuzzaman

Salinity interrupts osmoregulation, hinders water uptake, reduces water content, causes ionic toxicity, reduces chlorophyll content, alters stomatal conductance/movement, decreases enzymatic activity, alters transpiration and photosynthesis, disrupts the antioxidant defense system, and results in the oxidative burst. In turn, seed and oil yield is greatly declined. To overcome salinity-induced osmotic and ionic stress, plants evolve avoidance or tolerance mechanisms in order to protect the cellular components from sustaining growth and development. Ion homeostasis, vacuolar compartmentalization, accumulation of secondary metabolites, hormonal regulation, osmolytes production and by activating defensive responses, plants endure the salinity-induced damages, and enhance the stress tolerance. However, these salt-tolerant traits are greatly varied with species and genotypes as well as the extent of salt stress. Therefore, precise studies in understanding the physiology and molecular biology of stress are important to understand Brassica oilseed crops’ responses and tolerance to salt stress. In this chapter, we summarize the recent findings on the Brassica plants’ response to salt stress and later discuss the possible ways to enhance salt stress tolerance.

Part of the book: Oilseed Crops

By Mirza Hasanuzzaman, Faomida Sinthi, Samiul Alam, Abida Sultana, Samiha Rummana and Amena Khatun

Plants face various abiotic stresses, among which soil salinity is a significant threat. It reduces plants’ growth and development remarkably due to its detrimental effects. Salt stress occurs when soluble salts accumulate in the soil solution. A considerable portion of the world’s soil is negatively impacted by salinity, even at low concentrations. Salinity can hinder plant physiological processes by inducing osmotic stress and ionic toxicity, generating excessive reactive oxygen species (ROS) and leading to oxidative stress within plant cells. The formation of ROS is a normal plant metabolic phenomenon, but excessive ROS-induced oxidative stress can disrupt membrane activities, enzymes, and cell walls, cause cell damage, and, in severe cases, plant death. Various strategies, such as chemical substances and plant growth-promoting substances, are applied exogenously to diminish ROS-induced oxidative stress. Additionally, the use of rhizobacteria that have plant growth-promoting traits, organic amendments, rhizospheric fungi, and various genetic approaches are considered when addressing salt stress in plants. These mechanisms for scavenging ROS enhance plants’ tolerance to saline stress by developing an antioxidant defense system, reducing oxidative damage at the cellular level, and maintaining ion homeostasis. This chapter focuses on the latest research regarding the alleviation of salinity-induced oxidative stress in several crops through the exogenous application of stress elicitors.

Part of the book: Abiotic Stress in Crop Plants