Among abiotic stresses, salinity is a major global threat to agriculture, causing severe damage to crop production and productivity. Potato (Solanum tuberosum) is regarded as a future food crop by ...FAO to ensure food security, which is severely affected by salinity. The growth of the potato plant is inhibited under salt stress due to osmotic stress-induced ion toxicity. Salinity-mediated osmotic stress leads to physiological changes in the plant, including nutrient imbalance, impairment in detoxifying reactive oxygen species (ROS), membrane damage, and reduced photosynthetic activities. Several physiological and biochemical phenomena, such as the maintenance of plant water status, transpiration, respiration, water use efficiency, hormonal balance, leaf area, germination, and antioxidants production are adversely affected. The ROS under salinity stress leads to the increased plasma membrane permeability and extravasations of substances, which causes water imbalance and plasmolysis. However, potato plants cope with salinity mediated oxidative stress conditions by enhancing both enzymatic and non-enzymatic antioxidant activities. The osmoprotectants, such as proline, polyols (sorbitol, mannitol, xylitol, lactitol, and maltitol), and quaternary ammonium compound (glycine betaine) are synthesized to overcome the adverse effect of salinity. The salinity response and tolerance include complex and multifaceted mechanisms that are controlled by multiple proteins and their interactions. This review aims to redraw the attention of researchers to explore the current physiological, biochemical and molecular responses and subsequently develop potential mitigation strategies against salt stress in potatoes.
Tomato is an important vegetable that is highly sensitive to drought (DR) stress which impairs the development of tomato seedlings. Recently, melatonin (ME) has emerged as a nontoxic, regulatory ...biomolecule that regulates plant growth and enhances the DR tolerance mechanism in plants. The present study was conducted to examine the defensive role of ME in photosynthesis, root architecture, and the antioxidant enzymes' activities of tomato seedlings subjected to DR stress. Our results indicated that DR stress strongly suppressed growth and biomass production, inhibited photosynthesis, negatively affected root morphology, and reduced photosynthetic pigments in tomato seedlings. Per contra, soluble sugars, proline, and ROS (reactive oxygen species) were suggested to be improved in seedlings under DR stress. Conversely, ME (100 µM) pretreatment improved the detrimental-effect of DR by restoring chlorophyll content, root architecture, gas exchange parameters and plant growth attributes compared with DR-group only. Moreover, ME supplementation also mitigated the antioxidant enzymes APX (ascorbate peroxidase), CAT (catalase), DHAR (dehydroascorbate reductase), GST (glutathione S-transferase), GR (glutathione reductase), MDHAR (monodehydroascorbate reductase), POD (peroxidase), and SOD (superoxide dismutase), non-enzymatic antioxidant AsA (ascorbate), DHA (dehydroascorbic acid), GSH (glutathione), and GSSG, (oxidized glutathione) activities, reduced oxidative damage EL (electrolyte leakage), H
O
(hydrogen peroxide), MDA (malondialdehyde), and O
(superoxide ion) and osmoregulation (soluble sugars and proline) of tomato seedlings, by regulating gene expression for
,
,
,
,
,
,
, and
. These findings determine that ME pretreatment could efficiently improve the seedlings growth, root characteristics, leaf photosynthesis and antioxidant machinery under DR stress and thereby increasing the seedlings' adaptability to DR stress.
In this study, a reduced-reference image-quality-assessment (IQA) method for screen content images, named as feature-quality-index (FQI) is proposed. The proposed method is based on the fact that the ...human visual system is more sensitive towards change in features than intensity or structure. Reduced features from the reference and distorted images are first extracted. In order to find the preserved features in the distorted image, a feature matching process with a reduced number of distance calculations is proposed, namely reduced-distance method. To reflect the importance of the matched features and their distance, the inner product between the normalised scale and distance vector is obtained. Extensive comparisons are performed on two available benchmark databases namely SIQAD and QACS, with eight reduced-reference, and nine full-reference state-of-the-art IQA techniques to demonstrate the consistency, accuracy, and robustness of the proposed FQI. The subjective evaluation of mean opinion score shows that FQI outperforms the current state-of-the-art IQA techniques.
Potatoes are developed vegetatively from tubers, and therefore potato virus transmission is always a possibility. The potato leafroll virus (PLRV) is a highly devastating virus of the genus ...Polerovirus and family Luteoviridae and is regarded as the second-most destructive virus after Potato virus Y. Multiple species of aphids are responsible for the persistent and non-propagating transmission of PLRV. Due to intrinsic tuber damage (net necrosis), the yield and quality are drastically diminished. PLRV is mostly found in phloem cells and in extremely low amounts. Therefore, we have attempted to detect PLRV in both potato tuber and leaves using a highly sensitive, reliable and cheap method of one-step reverse transcription-recombinase polymerase amplification (RT-RPA). In this study, an isothermal amplification and detection approach was used for efficient results. Out of the three tested primer sets, one efficiently amplified a 153-bp product based on the coat protein gene. In the present study, there was no cross-reactivity with other potato viruses and the optimal amplification reaction time was thirty minutes. The products of RT-RPA were amplified at a temperature between 38 and 42 °C using a simple heating block/water bath. The present developed protocol of one-step RT-RPA was reported to be highly sensitive for both leaves and tuber tissues equally in comparison to the conventional reverse transcription-polymerase chain reaction (RT-PCR) method. By using template RNA extracted employing a cellular disc paper-based extraction procedure, the method was not only simplified but it detected the virus as effectively as purified total RNA. The simplified one-step RT-RPA test was proven to be successful by detecting PLRV in 129 samples of various potato cultivars (each consisting of leaves and tubers). According to our knowledge, this is the first report of a one-step RT-RPA performed using simple RNA extracted from cellular disc paper that is equally sensitive and specific for detecting PLRV in potatoes. In terms of versatility, durability and the freedom of a highly purified RNA template, the one-step RT-RPA assay exceeds the RT-PCR assay, making it an effective alternative for the certification of planting materials, breeding for virus resistance and disease monitoring.
Potato dry rot disease caused by
Fusarium
species is a major threat to global potato production. The soil and seed-borne diseases influence the crop stand by inhibiting the development of potato ...sprouts and cause severe rots in seed tubers, table and processing purpose potatoes in cold stores. The symptoms of the dry rot include sunken and wrinkled brown to black tissue patches on tubers having less dry matter and shriveled flesh. Fungal infection accompanied by toxin development in the rotten tubers raises more concern for consumer health. The widespread dry rot causing fungal species (
Fusarium graminearum
) is reported to have a hemibiotrophic lifestyle. A cascade of enzymes, toxins and small secreted proteins are involved in the pathogenesis of these hemibiotrophs. With the availability of the genome sequence of the most devastating species
Fusarium sambucinum,
it is important to identify the potential pathogenicity factors and small secreted proteins that will help in designing management strategies. Limited resistant cultivars and the emergence of fungicide-resistant strains have made it more threatening for potato cultivation and trade. Several novel fungicide molecules (Azoxystrobin, chlorothalonil and fludioxonil), are found very effective as tuber treatment chemicals. Besides, many beneficial bioagents and safer chemicals have shown antibiosis and mycoparasitism against this pathogen. Germplasm screening for dry rot resistance is important to assist the resistance breeding program for the development of resistant cultivars. This review aims to draw attention to the symptomatology, infection process, pathogenomics, the role of toxins and management approaches for potato dry rot disease, which is very much critical in designing better management strategies.
Cotton (
L.) is one of the most important staple fibrous crops cultivated in India and globally. However, its production and quality are greatly hampered by cotton leaf curl disease (CLCuD) caused by ...cotton leaf curl virus (CLCuV). Therefore, the aim of the present study was to investigate the biochemical mechanisms associated with CLCuD resistance in contrasting cotton genotypes.
Four commercial cotton varieties with susceptible (HS 6 and RCH-134 BG-II) and resistant (HS 1236 and Bunty) responses were used to analyze the role of primary (sugar, protein, and chlorophyll) and secondary (gossypol, phenol, and tannin) biochemical compounds produced by the plants against infection by CLCuV. The resistant cultivars with increased activity of protein, phenol, and tannin exhibited biochemical barriers against CLCuV infection, imparting resistance in cotton cultivars.
Reducing sugar in the healthy plants of the susceptible Bt cultivar RCH 134 BG-II exhibited the highest value of 1.67 mg/g at 90 days. In contrast, the lowest value of 0.07 mg g
was observed at 60 DAS in the highly diseased plants of the susceptible hybrid HS 6. Higher phenol content (0.70 mg g
) was observed at 90 DAS in resistant cultivars, whereas highly susceptible plants exhibited the least phenol (0.25 mg g
) at 90 DAS. The lowest protein activity was observed at 120 DAS in susceptible cultivars HS 6 (9.4 mg g
) followed by RCH 134 BG-II (10.5 mg g
). However, other biochemical compounds, including chlorophyll, sugar, and gossypol, did not show a significant role in resistance against CLCuV. The disease progression analysis in susceptible cultivars revealed non-significant differences between the two susceptible varieties.
Nevertheless, these compounds are virtually associated with the basic physiological and metabolic mechanisms of cotton plants. Among the primary biochemical compounds, only protein activity was proposed as the first line of defense in cotton against CLCuV. The secondary level of defense line in resistance showed the activity of secondary biochemical compounds phenol and tannins, which displayed a significant increase in their levels while imparting resistance against CLCuV in cotton.
Mungbean is a vital pulse crop in India that can thrive in dry-land conditions and is grown in three seasons, with the added benefit of being used as green manure due to its ability to fix ...atmospheric nitrogen. Recently, pod rot disease has emerged as a serious threat to mungbean cultivation in India.
In this study, morpho-molecular identification of associated pathogens and the bio-efficacy of systemic and non-systemic fungicides as well as genotype screening was performed during the years 2019 and 2020. The pathogens associated with this disease were confirmed on the basis of morphological and molecular characterization. For the molecular characterization, the translation elongation factor 1-alpha (tef-1) gene sequences were amplified by using primers (EF1 and EF2).
Under in vitro conditions, trifloxystrobin + tebuconazole 75% WG was found to be the most effective against Fusarium equiseti (ED
2.39 μg ml
) and Fusarium chlamydosporum (ED
4.23 μg ml
) causal agents of pod rot of mungbean. Under field conditions, three applications of trifloxystrobin + tebuconazole 75% WG at 0.07% as a foliar application at fortnightly intervals starting from the last week of July proved to be the most effective against pod rot disease on mungbean cultivars, i.e., ML 2056 and SML 668. To identify the potential resistance sources, 75 interspecific derivative and mutant lines of mungbean were screened for disease reaction to pod rot under natural epiphytotic conditions for the years 2019 and 2020. Genotypic differences were observed for resistance to pod rot disease. The study revealed that among the tested genotypes, ML 2524 exhibited resistance to pod rot disease, with a disease incidence of 15.62% and disease severity of 7.69%. In addition, 41 other genotypes were found to be moderately resistant (MR) to the disease.
Altogether, the identified management options will offer an immediate solution to manage this disease under recent outbreak conditions and pave a path for futuristic disease management using identified resistant sources in breeding programs.
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