To ward off pathogens and pests, plants use a sophisticated immune system. They use pattern-recognition receptors (PRRs), as well as nucleotide-binding and leucine-rich repeat (NB-LRR) domains, for ...detecting nonindigenous molecular signatures from pathogens. Plant PRRs induce local and systemic immunity. Plasma-membrane-localized PRRs are the main components of multiprotein complexes having additional transmembrane and cytosolic kinases. Topical research involving proteins and their interactive partners, along with transcriptional and posttranscriptional regulation, has extended our understanding of R-gene-mediated plant immunity. The unique LRR domain conformation helps in the best utilization of a surface area and essentially mediates protein-protein interactions. Genome-wide analyses of inter- and intraspecies PRRs and NB-LRRs offer innovative information about their working and evolution. We reviewed plant immune responses with relevance to PRRs and NB-LRRs. This article focuses on the significant functional diversity, pathogen-recognition mechanisms, and subcellular compartmentalization of plant PRRs and NB-LRRs. We highlight the potential biotechnological application of PRRs and NB-LRRs to enhance broad-spectrum disease resistance in crops.
Small RNAs (sRNA) are a significant group of gene expression regulators for multiple biological processes in eukaryotes. In plants, many sRNA silencing pathways produce extensive array of sRNAs with ...specialized roles. The evidence on record advocates for the functions of sRNAs during plant microbe interactions. Host sRNAs are reckoned as mandatory elements of plant defense. sRNAs involved in plant defense processes via different pathways include both short interfering RNA (siRNA) and microRNA (miRNA) that actively regulate immunity in response to pathogenic attack via tackling pathogen-associated molecular patterns (PAMPs) and other effectors. In response to pathogen attack, plants protect themselves with the help of sRNA-dependent immune systems. That sRNA-mediated plant defense responses play a role during infections is an established fact. However, the regulations of several sRNAs still need extensive research. In this review, we discussed the topical advancements and findings relevant to pathogen attack and plant defense mediated by sRNAs. We attempted to point out diverse sRNAs as key defenders in plant systems. It is hoped that sRNAs would be exploited as a mainstream player to achieve food security by tackling different plant diseases.
Lodging is a factor that negatively affects yield, seed quality, and harvest ability in winter rapeseed (Brassica napus L.). In this study, we quantified the lodging-induced yield losses, changes in ...fatty acid composition, and oil quality in rapeseed under different nitrogen application rates and planting densities. Field experiments were conducted in 2014-2017 for studying the effect of manually-induced lodging angles (0°, 30°, 60°, and 90°), 10, 20 and 30 d post-flowering at different densities and nitrogen application rates. The fertilization/planting density combination N
D
produced the maximum observed yield and seed quality. Timing and angle of lodging had significant effects on yield. Lodging at 90° induced at 10 d post-flowering caused the maximum reduction in yield, biomass, and silique photosynthesis. Seed yield losses were higher at high N application rates, the maximum being at N
D
. Lodging decreased seed oil content and altered its fatty acid composition by increasing stearic and palmitic acid content, while decreasing linoleic and linolenic acid content, and deteriorating oil quality by increasing erucic acid and glucosinolate content. Therefore, lodging-induced yield loss and reduction in oil content might be reduced by selecting optimum N level and planting density.
9-cis-epoxycarotenoid dioxygenase (NCED) is the rate-limiting enzyme for abscisic acid (ABA) biosynthesis in higher plants. In rice, OsNCED3 was shown to promote ABA synthesis, and improve abiotic ...stress tolerance, but the function of OsNCED3 in regulating rice defense against the brown planthopper (Nilaparvata lugens; BPH) has been unclear. In this study, several parameters were used to assess rice resistance to BPH, including the average injury level, the functional plant loss index, and electrical penetration graph analysis. Rice lines overexpressing OsNCED3 (OE) were more resistant to BPH than the wild-type cv. Zhonghua11 (WT). Transcriptome analysis was performed on WT, OE, and a RNAi transgenic line silenced for OsNCED3; these three lines were either infested or non-infested with BPH. Seventeen RNA libraries were compared, and most of the differentially expressed genes (DEGs) were upregulated. The number of DEGs in the RNAi line infested with BPH was significantly higher than the OE, and WT lines, and many DEGs were related to the stress response, and biosynthesis of jasmonic acid. This study shows that overexpression of OsNCED3 in rice improves resistance to BPH, and has potential merit in rice breeding programs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Water shortage appears to be expedited under the current climate change scenario worldwide. The present work was aimed to investigate the effects of zinc-chelated lysine (Zn-Lys) on germination and ...yield of water stressed radish plants. The research was comprised of two studies where the effect of Zn-Lys seed priming on germination attributes under PEG-induced water stress was investigated in the first experiment. In the second experiment, growth, physio-biochemical, and yield responses of water-stressed radish plants raised from Zn-Lys primed seeds were recorded. The seeds pre-conditioned with 0, 1.5, 3, 4.5, or 6 mg kg−1 of Zn-Lys was grown in petri-dishes and pots. Priming treatments significantly improved the germination attributes under water stress. Plants raised from primed seeds exhibited significant improvements in plant biomass production, leaf photosynthetic pigments, final root yield, and nutritional quality. Furthermore, the activities of superoxide dismutase (SOD) and peroxidase (POD) were increased, while the melondialdehyde (MDA) content decreased. Root flavonoids, ascorbic acid, carotenoids, protein, carbohydrates, fiber and lysine content were significantly improved due to Zn-Lys seed priming, both under water-stressed and non-stressed conditions. Moreover, plant's mineral nutrients such as K and Ca as well as Mg, Fe, P, and Zn of final harvested roots were also improved due to Zn-Lys seed priming. Overall, for the induction of drought tolerance and nutritional quality, Zn-Lys regimes of 3 and 4.5 mg kg−1 were most effective. It can be inferred that the Zn-Lys priming maintained a potential balance of nutrient uptake and translocation by preventing drought-induced lipid peroxidation of membranes.
•Water shortage appears to be expedited under the current worldwide climate change scenario.•Zn is essentially required for the metabolism of proteins, carbohydrates, phosphates, auxins and nucleic acid synthesis.•The nutrient solutions having amino acids present enhanced absorption, an effect due to their chelating property.•Plants from Zn-Lys primed seeds exhibited improvement in biomass, photosynthetic pigments, yield and nutritional quality.•The utilization of Zn-Lys maintained nutrient uptake and translocation by preventing drought-induced membrane lipid peroxidation.
Concerns about motor vehicle emissions on human health are typically focused on aerial pollution and are regulated via controls on tailpipe emissions. However, vehicles also contribute heavy metal ...emissions through non-tailpipe pathways (e.g., brake wear, tire particulates). The metal pollutants produced via both tailpipe and non-tailpipe pathways pose threats to both human and ecosystem health long after they have settled from the atmosphere largely via contamination of soils and plants. In this study, we examined the effect of vehicular pollution on soils and plants in five paired sites in Gaviota, CA. In each site, we examined the effect of proximity to road on heavy metal concentrations (cadmium, nickel, lead, and zinc) in four of the most common roadside plant species—
Melilotus indicus
,
Herschfeldia incana
,
Avena sativa
, and
Artemisia californica—
as well as on soil metal concentrations. Then, to look at potential effects of road proximity and associated metal pollution on plants, we also examined the carbon and nitrogen ratios of all the plant samples. We found strong and significant effects of proximity to road on concentrations of all heavy metals in plants; plants in close proximity to roads had metal concentrations between 8 and 11 times higher than plants farther from roads. Plant C:N ratios also varied strongly among site types and were always higher in close proximity to roads as compared to farther off roads, potentially indicating broader effects of road proximity to plant ecology and leaf quality for consumers in the region.
Brassinosteroids (BRs) are well-ascertained growth regulators that play prime roles in alleviation of a stress in plants. The current investigation determined the impact of epibrassinolide (EBR) ...applied as seed pretreatment on growth attributes, physiological attributes and antioxidant potential of tomato plants grown under Cr(VI) metal stress. Applications of EBR were found to be effective in improving growth of control as well as Cr-stressed plants in terms of lengths of shoot and root and their dry weights. Of the physiological parameters, stomatal conductance was the most sensitive to chromium exposure exhibiting 72.15% decline, while photosynthetic rate decreased to 33.16%. Chromium stress led to decline in non-enzymatic antioxidants like GSH by 41.85% and in total flavonoid by 69.48%. Application of EBR modulated more significantly the titres of antioxidants (glutathione, ascorbic acid, total flavonoids and activities of antioxidant enzymes (ascorbate peroxidase, catalase, superoxide dismutase, glutathione-
S
-transferase and glutathione reductase) as well as proline and glycine betaine in Cr-stressed plants compared to those in plants receiving no supply of EB. Diminution of Cr stress by EBR was also maintained by higher values of stress indices, such as flavonoids, photosynthetic pigments and reduction in malondialdehyde and H
2
O
2
levels in the Cr-treated plants than those in the controls. Restricted production of ROS and improved quenching of ROS were also recorded due to EBR application under Cr stress. At the same time, insignificant reduction in uptake of Cr was noticed due to application of EBR in leaves compared to that in roots of Cr-stressed plants. Overall, our results reveal that application of EBR can effectively act as a growth stimulant in plants subjected to Cr stress. Therefore, it can be conjectured that the interaction of 24-epibrassinolide remodulates the physiological, metabolic and defence system of the tomato thriving under chromium stress by equilibrating the Cr accumulation.
The WRKY web, which is comprised of a subset of WRKY transcription factors (TFs), plays a crucial role in the regulation of plant immunity, however, the mode of organization and operation of this ...network remains obscure, especially in non-model plants such as pepper (
). Herein,
, a member of a subgroup of IIe WRKY proteins from pepper, was functionally characterized in pepper immunity against
. CaWRKY22 was found to target the nuclei, and its transcript level was significantly upregulated by
inoculation (RSI) and exogenously applied salicylic acid (SA), Methyl jasmonate (MeJA), or ethephon (ETH). Loss-of-function
, caused by virus-induced gene silencing (VIGS), enhanced pepper's susceptibility to RSI. In addition, the silencing of
perturbed the hypersensitive response (HR)-like cell death elicited by RSI and downregulated defense-related genes including
,
,
,
,
,
, and
. CaWRKY22 was found to directly bind to the promoters of
,
, and
by chromatin immuno-precipitation (ChIP) analysis. Contrastingly, transient overexpression of
in pepper leaves triggered significant HR-like cell death and upregulated the tested immunity associated maker genes. Moreover, the transient overexpression of
upregulated the expression of
and
while it downregulated of the expression of
. Conversely, the transient overexpression of
,
, and
upregulated the expression of
, while transient overexpression of
downregulated the transcript levels of
. These data collectively recommend the role of CaWRKY22 as a positive regulator of pepper immunity against
, which is regulated by signaling synergistically mediated by SA, jasmonic acid (JA), and ethylene (ET), integrating into WRKY networks with WRKY TFs including CaWRKY6, CaWRKY27, CaWRKY40, and CaWRKY58.
This review paper describes a novel approach to plant cultivation under soil-less culture. At present, global climate change is expected to raise the risk of frequent drought. Agriculture is in a ...phase of major change around the world and dealing with serious problems. In future, it would be difficult task to provide a fresh and clean food supply for the fast-growing population using traditional agriculture. Under such circumstances, the soil-less cultivation is the alternative technology to adapt effectively. The soil-less system associated with the Hydroponic and Aeroponics system. In the aeroponics system, plant roots are hanging in the artificially provided plastic holder and foam material replacement of the soil under controlled conditions. The roots are allowed to dangle freely and openly in the air. However, the nutrient rich-water deliver with atomization nozzles. The nozzles create a fine spray mist of different droplet size at intermittently or continuously. This review concludes that aeroponics system is considered the best plant growing method for food security and sustainable development. The system has shown some promising returns in various countries and recommended as the most efficient, useful, significant, economical and convenient plant growing system then soil and other soil-less methods.
The soil microbiome comprises one of the most important and complex components of all terrestrial ecosystems as it harbors millions of microbes including bacteria, fungi, archaea, viruses, and ...protozoa. Together, these microbes and environmental factors contribute to shaping the soil microbiome, both spatially and temporally. Recent advances in genomic and metagenomic analyses have enabled a more comprehensive elucidation of the soil microbiome. However, most studies have described major modulators such as fungi and bacteria while overlooking other soil microbes. This review encompasses all known microbes that may exist in a particular soil microbiome by describing their occurrence, abundance, diversity, distribution, communication, and functions. Finally, we examined the role of several abiotic factors involved in the shaping of the soil microbiome.
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