Plant Biotechnology Reports 

About: Plant Biotechnology Reports is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Gene & Biology. It has an ISSN identifier of 1863-5466. Over the lifetime, 805 publications have been published receiving 12924 citations.

Nitric oxide modulates antioxidant defense and the methylglyoxal detoxification system and reduces salinity-induced damage of wheat seedlings

Abstract: The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in antioxidant defense and methylglyoxal (MG) detoxification systems of wheat seedlings exposed to salt stress (150 and 300 mM NaCl, 4 days). Seedlings were pre-treated for 24 h with 1 mM sodium nitroprusside, a NO donor, and then subjected to salt stress. The ascorbate (AsA) content decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) and the GSH/GSSG ratio increased with an increase in the level of salt stress. The glutathione S-transferase (GST) activity increased significantly with severe salt stress (300 mM). The ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glutathione peroxidase (GPX) activities did not show significant changes in response to salt stress. The glutathione reductase (GR), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased upon the imposition of salt stress, especially at 300 mM NaCl, with a concomitant increase in the H2O2 and lipid peroxidation levels. Exogenous NO pre-treatment of the seedlings had little influence on the non-enzymatic and enzymatic components compared to the seedlings of the untreated control. Further investigation revealed that NO pre-treatment had a synergistic effect; that is, the pre-treatment increased the AsA and GSH content and the GSH/GSSG ratio, as well as the activities of MDHAR, DHAR, GR, GST, GPX, Gly I, and Gly II in most of the seedlings subjected to salt stress. These results suggest that the exogenous application of NO rendered the plants more tolerant to salinity-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems.

Fundamentals and applications of light-emitting diodes (LEDs) in in vitro plant growth and morphogenesis

Abstract: Advances in plant tissue culture methods with regard to lighting requirements are currently focused on the improved features of light-emitting diodes (LEDs). Over the years, the steady development of LED technology, with the emergence of new types of semi-conductor materials, has made it possible to apply it in an increasing number of new areas. As an alternative to conventional lighting systems, LED has been demonstrated to be an artificial flexible lighting source for plant tissue culture. Numerous studies have been conducted in order to investigate the effects of LED on plants, which have led to many satisfactory results. Various morphological, anatomical, and physiological attributes, such as shoot elongation, axillary shoot formation, somatic embryo induction, rhizogenesis, leaf anatomy, and photosynthetic abilities of plants grown in vitro have found to be regulated by spectral properties of LEDs. The present review gives an overview of the fundamentals of LEDs and describes their effects on in vitro plant growth and morphogenesis and their future potentials.

Alterations in photosynthetic pigments, protein and osmotic components in cotton genotypes subjected to short-term drought stress followed by recovery

Abstract: In order to assess drought tolerance mechanism in cotton, short-term drought-induced biochemical responses were monitored in two cotton (Gossypium hirsutum L.) genotypes contrasting their tolerance to water deficit. The seeds of two genotypes, namely GM 090304 (moderately drought tolerant) and Ca/H 631 (drought sensitive), were sown in pots containing soil, sand and peat in the ratio of 1:1:1, and irrigated every alternate day up to 45 days after sowing when each genotype was subjected to a cycle of water stress by withholding irrigation for 7 days. The stress cycle was terminated by re-watering the stressed plants for 7 days. The leaf of the drought tolerant genotype (GM 090304) maintained higher relative water content under water stress than that of the drought sensitive genotype (Ca/H 631). The levels of biochemical components, such as chlorophylls, carotenoids, total protein, free proline, total free amino acids, sugars, starch and polyphenols, were measured during the stress as well as the recovery periods. The chlorophylls, carotenoids, protein and starch contents decreased in drought stressed plants as compared to control and tended to increase when the plants were recovered from stress. The degree of decrease in chlorophylls, carotenoids and protein contents under drought was higher in the sensitive genotype (Ca/H 631) as compared to the moderately tolerant genotype (GM 090304). However, proline, total free amino acids, total sugars, reducing sugars and polyphenol contents were increased in drought stressed plants and tended to decrease during the period of recovery. Drought-induced increases in total free amino acids, proline, sugars and polyphenols were significantly higher in the moderately tolerant genotype (GM 090304) than in the sensitive genotype (Ca/H 631). These results suggest that proline, sugars and polyphenols act as main compatible solutes in cotton in order to maintain osmotic balance, to protect cellular macromolecules, to detoxify the cells, and to scavenge free radicals under water stress condition.

Use of plant growth-promoting rhizobacteria to control stress responses of plant roots.

Abstract: Ethylene is a key gaseous hormone that controls various physiological processes in plants including growth, senescence, fruit ripening, and responses to abiotic and biotic stresses. In spite of some of these positive effects, the gas usually inhibits plant growth. While chemical fertilizers help plants grow better by providing soil-limited nutrients such as nitrogen and phosphate, over-usage often results in growth inhibition by soil contamination and subsequent stress responses in plants. Therefore, controlling ethylene production in plants becomes one of the attractive challenges to increase crop yields. Some soil bacteria among plant growth-promoting rhizobacteria (PGPRs) can stimulate plant growth even under stressful conditions by reducing ethylene levels in plants, hence the term “stress controllers” for these bacteria. Thus, manipulation of relevant genes or gene products might not only help clear polluted soil of contaminants but contribute to elevating the crop productivity. In this article, the beneficial soil bacteria and the mechanisms of reduced ethylene production in plants by stress controllers are discussed.

Enhanced proline accumulation and salt stress tolerance of transgenic indica rice by over-expressing P5CSF129A gene

Abstract: Δ1-pyrroline-5-carboxylate synthetase (P5CS) is a proline biosynthetic pathway enzyme and is known for conferring enhanced salt and drought stress in transgenics carrying this gene in a variety of plant species; however, the wild-type P5CS is subjected to feedback control. Therefore, in the present study, we used a mutagenized version of this osmoregulatory gene-P5CSF129A, which is not subjected to feedback control, for producing transgenic indica rice plants of cultivar Karjat-3 via Agrobacterium tumefaciens. We have used two types of explants for this purpose, namely mature embryo-derived callus and shoot apices. Various parameters for transformation were optimized including antibiotic concentration for selection, duration of cocultivation, addition of phenolic compound, and bacterial culture density. The resultant primary transgenic plants showed more enhanced proline accumulation than their non-transformed counterparts. This proline level was particularly enhanced in the transgenic plants of next generation (T1) under 150 mM NaCl stress. The higher proline level shown by transgenic plants was associated with better biomass production and growth performance under salt stress and lower extent of lipid peroxidation, indicating that overproduction of proline may have a role in counteracting the negative effect of salt stress and higher maintenance of cellular integrity and basic physiological processes under stress.