Tropical Plant Research 

About: Tropical Plant Research is an academic journal. The journal publishes majorly in the area(s): Flora & Germination. Over the lifetime, 402 publications have been published receiving 1311 citations.

Endogenous glycine betaine accumulation mediates abiotic stress tolerance in plants

Abstract: Abiotic stresses like salinity, drought, cold, high temperature, etc. are largely responsible for a considerable degree of annual crop losses worldwide. Till date, several effectors have been reported which confer stress tolerance to the plants. Glycine betaine (GB) is one such important regulator which accumulates in the cell as a crucial osmolyte and alleviates the cell from damages due to salinity, drought, temperature and oxidative stresses. This has been verified through several investigations at the physiological, biochemical and molecular levels. Apart from acting as an important compatible solute, GB has a prominent role in maintaining cellular homeostasis and mediating chaperone activity to prohibit undesirable protein folding under stress. The protective role of exogenous applications of GB in crops is also a well-studied fact. In addition, several detailed literatures are available on the transgenic technology and on-field tests which have depicted the increasing stress tolerance developed in plants accumulating higher levels of endogenous GB. All these issues have been reviewed and documented in the present

Assessment of diversity, population structure and regeneration status of tree species in Hollongapar Gibbon Wildlife Sanctuary, Assam, Northeast India

Abstract: The present study was carried out for quantitative analysis of diversity, population structure and regeneration status of tree species in tropical semi-evergreen forest of Hollongapar Gibbon Wildlife Sanctuary, Assam, northeast India. The study was conducted during 2010-2011, by laying 100 quadrats (10×10m) following random plot sampling method. A total of 75 tree species (≥30 cm gbh), belonging to 60 genera and 40 families were recorded from the study area. Individuals were categorized into three groups, seedling, sapling and adult based on girth classes and the status of natural regeneration of species was determined based on their population size. Highest density (7756 individuals ha - ¹) and species richness (73) were recorded in 0-30 cm girth class, while highest basal area (9.62 m² ha - ¹) was observed in 120-150 cm girth class. Majority of tree species (36%) exhibited "fair regeneration" condition followed by "good regeneration" status (24%). The overall population structure of tree species shows a reverse J-shaped population curve and "good" regeneration status which reveals that the future communities may be sustained. The study gives an understanding of the diversity, pattern of population and regeneration of the tree species of the sanctuary which may help in forest management and conservation of the species.

Plants responses and their physiological and biochemical defense mechanisms against salinity: A review

Abstract: Plants confront an extent of abiotic stresses due to environmental hardship, among which salinity is one of the major abiotic stresses that seizes plant growth and development resulting in a massive yield loss worldwide. Plants respond to salinity in two distinct phases: a quick osmotic phase and a sluggish ionic phase also known as hyper osmotic phase. Plants adjustment and/or tolerance to salinity stress comprise several complex physiological, biochemical and molecular networks. A widespread understanding of how plants response to salinity stress at different phases, and a cohesive physiological and biochemical approaches are crucial for the development of salt adapted and/or tolerant varieties for salt-affected areas. Researchers have identified several adaptive responses to salinity stress at cellular, biochemical and physiological levels, even though mechanisms triggering salt stress adaptation and/or tolerance are far from being entirely understood. This article bestows a spacious review of foremost research advances on physiological and biochemical mechanisms governing plant adaptation and/or tolerance to salinity stress relevant to environmental sustainability and as well as food production.

Effect of salinity on osmolytes and relative water content of selected rice genotypes

Abstract: Reduction in relative water content (RWC) and photosynthesis (dry matter) is a common effect of salinity stress. In the present study, 7 days old rice plants were exposed to 0 (control) and 100 mM NaCl salinity for 7 days to determine the osmolytes accumulation and relative water content (RWC) in leaves. We observed that shoot dry matter, relative water content and K content decreased significantly with the increasing of salinity. In contrast, Na and proline content excessively increased in the leaves of salinity stressed plant. The results revealed that both the organic (proline) and inorganic (K) osmolytes accumulation may be responsible for stress alleviation by retaining water in cell.

Seed priming with spermine ameliorates salinity stress in the germinated seedlings of two rice cultivars differing in their level of salt tolerance

Abstract: The present study was aimed to assess the efficacy of the tetramine, spermine (Spm) as a seed priming agent in attenuating oxidative damages and improving salt tolerance in salt-stressed seedlings of IR-64 (salt-sensitive) and Nonabokra (salt-tolerant) rice cultivars. The extent of damages was lesser in Nonabokra due to higher cysteine and ascorbic acid (AA), reducing power ability, concomitant with unaltered ascorbic acid oxidase (AAO) activity, and elevated ascorbate peroxidase (APX) and α-amylase activity. Spm priming alleviated salt stress injury by lowering the malondialdehyde and H2O2 content and avoiding chlorophyll degeneration in both the cultivars, the effect being more pronounced in IR-64 in terms of H2O2 reduction. The intrinsic property of Spm in stress amelioration was highly evident with respect to the reduction in the levels of anthocyanin, total phenolics and cysteine, and activity of AAO and superoxide dismutase (SOD) in IR-64, whereas lowered guaiacol peroxidase (GPX), catalase (CAT) and SOD activity in Nonabokra, as compared to Spm non-primed stressed-seedlings. However, Spm priming enhanced the reducing power ability, GPX, α-amylase and polyphenol oxidase (PPO) activities in IR-64, and anthocyanin, AA and CAT activity in Nonabokra, as means of mitigating cellular NaCl toxicity. A clear-cut variation in GPX, CAT, SOD and esterase isozyme profile was discernible between the two cultivars during salinity stress, with specific isoform(s) being up regulated or down regulated with Spm pre-treatment. In terms of osmolyte regulation, Spm priming appeared to be more promising in Nonabokra, because of the enhanced levels of reducing sugar, amino acids and proline. All these results indicated that seed priming with Spm at the pre-sowing stage can promote salinity tolerance with varying degrees in the two rice cultivars by attenuating oxidative damages, triggering the antioxidants and osmolytes, and activating the antioxidative enzymes at the protein level.