The Receptor-Like Kinase （RLK） is a vast protein family with over 600 genes in Arabidopsis and 1100 in rice. The Lectin RLK （LecRLK） family is believed to play crucial roles in saccharide signaling ...as well as stress perception. All the LecRLKs possess three domains： an N-terminal lectin domain, an intermediate transmembrane domain, and a C-terminal kinase domain. On the basis of lectin domain variability, LecRLKs have been subgrouped into three subclasses： L-, G-, and C-type LecRLKs. While the previous studies on LecRLKs were dedicated to classification, comparative structural analysis and expression analysis by promoter-based studies, most of the recent studies on LecRLKs have laid special emphasis on the potential of this gene family in regulating biotic/abiotic stress and developmental pathways in plants, thus mak- ing the prospects of studying the LecRLK-mediated regulatory mechanism exceptionally promising. In this review, we have described in detail the LecRLK gene family with respect to a historical, evolutionary, and structural point of view. Furthermore, we have laid emphasis on the LecRLKs roles in development, stress conditions, and hormonal response. We have also discussed the exciting research prospects offered by the current knowledge on the LecRLK gene family. The multitude of the LecRLK gene family members and their functional diversity mark these genes as both interesting and worthy candidates for further analysis, especially in the field of crop improvement.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Rice (Oryza sativa L.), one of the most important food crop in the world, is considered to be a salt-sensitive crop. Excess levels of salt adversely affect all the major metabolic activities, ...including cell wall damage, cytoplasmic lysis and genomic stability. In order to cope with salt stress, plants have evolved high degrees of developmental plasticity, including adaptation via cascades of molecular networks and changes in gene expression profiles. Posttranscriptional regulation, through the activity of microRNAs, also plays an important role in the plant response to salinity conditions. MicroRNAs are small endogenous RNAs that modulate gene expression and are involved in the most essential physiological processes, including plant development and adaptation to environmental changes.
In the present study, we investigated the expression profiles of osa-MIR414, osa-MIR408 and osa-MIR164e along with their targeted genes, under salinity stress conditions in wild type and transgenic rice plants ectopically expressing the PDH45 (Pea DNA Helicase) gene. The present miRNAs were predicted to target the OsABP (ATP-Binding Protein), OsDSHCT (DOB1/SK12/helY-like DEAD-box Helicase) and OsDBH (DEAD-Box Helicase) genes, included in the DEAD-box helicase family. An in silico characterization of the proteins was performed and the miRNAs predicted targets were validated by RLM-5'RACE. The qRT-PCR analysis showed that the OsABP, OsDBH and OsDSHCT genes were up-regulated in response to 100 and 200 mM NaCl treatments. The present study also highlighted an increased accumulation of the gene transcripts in wild type plants, with the exception of the OsABP mRNA which showed the highest level (15.1-fold change compared to control) in the transgenic plants treated with 200 mM NaCl. Salinity treatments also affected the expression of osa-MIR414, osa-MIR164e and osa-MIR408, found to be significantly down-regulated, although the changes in miRNA expression were limited.
Osa-MIR414, osa-MIR164e and osa-MIR408 were experimentally validated for the first time in plants as targeting the OsABP, OsDBH and OsDSHCT genes. Our data showed that that the genes were up-regulated and the miRNAs were down-regulated in relation to salt stress. The negative correlation between the miRNAs and their targets was proven.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Rice tungro disease (RTD) is a serious constraint in rice production across tropical Asia. RTD is caused by the interaction between Rice tungro spherical virus (RTSV) and Rice tungro ...bacilliform virus. RTSV resistance found in traditional cultivars has contributed to a reduction in the incidence of RTD in the field. Natural RTSV resistance is a recessive trait controlled by the translation initiation factor 4 gamma gene (eIF4G). The Y1059V1060V1061 residues of eIF4G are known to be associated with the reactions to RTSV. To develop new sources of resistance to RTD, mutations in eIF4G were generated using the CRISPR/Cas9 system in the RTSV‐susceptible variety IR64, widely grown across tropical Asia. The mutation rates ranged from 36.0% to 86.6%, depending on the target site, and the mutations were successfully transmitted to the next generations. Among various mutated eIF4G alleles examined, only those resulting in in‐frame mutations in SVLFPNLAGKS residues (mainly NL), adjacent to the YVV residues, conferred resistance. Furthermore, our data suggest that eIF4G is essential for normal development, as alleles resulting in truncated eIF4G could not be maintained in homozygous state. The final products with RTSV resistance and enhanced yield under glasshouse conditions were found to no longer contain the Cas9 sequence. Hence, the RTSV‐resistant plants with the novel eIF4G alleles represent a valuable material to develop more diverse RTSV‐resistant varieties.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
MicroRNAs (miRNAs), defined as small non-coding RNA molecules, are fine regulators of gene expression. In plants, miRNAs are well-known for regulating processes spanning from cell development to ...biotic and abiotic stress responses. Recently, miRNAs have been investigated for their potential transfer to distantly related organisms where they may exert regulatory functions in a cross-kingdom fashion. Cross-kingdom miRNA transfer has been observed in host-pathogen relations as well as symbiotic or mutualistic relations. All these can have important implications as plant miRNAs can be exploited to inhibit pathogen development or aid mutualistic relations. Similarly, miRNAs from eukaryotic organisms can be transferred to plants, thus suppressing host immunity. This two-way lane could have a significant impact on understanding inter-species relations and, more importantly, could leverage miRNA-based technologies for agricultural practices. Additionally, artificial miRNAs (amiRNAs) produced by engineered plants can be transferred to plant-feeding organisms in order to specifically regulate their cross-kingdom target genes. This minireview provides a brief overview of cross-kingdom plant miRNA transfer, focusing on parasitic and mutualistic relations that can have an impact on agricultural practices and discusses some opportunities related to miRNA-based technologies. Although promising, miRNA cross-kingdom transfer remains a debated argument. Several mechanistic aspects, such as the availability, transfer, and uptake of miRNAs, as well as their potential to alter gene expression in a cross-kingdom manner, remain to be addressed.
Cadmium (Cd2+) is a widespread heavy metal pollutant in the environment with a long biological half-life, originating mainly from industrial processes and phosphate fertilizers. It is easily taken up ...by plants, resulting in toxicity symptoms, such as chlorosis, wilting, growth reduction, and cell death. This cellular toxicity might result from interactions with vital metabolic pathways, carboxyl or thiol groups of proteins and reactive oxygen species (ROS) burst in plants. Plant exposure even to low concentrations of Cd may lead to cell death but the mechanism of its toxicity is still debatable. Therefore, exploring various ways to improve crop productivity and/or alleviate Cd stress effects is one of the major areas of concern. Nitric oxide (NO) is a hydrophobic gaseous molecule involved in various physiological processes such as germination, root growth, stomatal closure, control of the flowering timing etc. NO also functions as cell signaling molecule in plants and play important roles in the regulation of plant responses to both abiotic and biotic stress conditions. At the molecular level, NO signaling includes protein modification by binding to critical cysteine residues, heme or iron–sulfur centers and tyrosine residue nitration via peroxynitrite formation (ONOO−), mobilization of secondary messengers (Ca2+, cyclic GMP and cyclic ADP-Rib) and modulation of protein kinase activities. Significant research had been done to understand the NO biosynthesis and signaling in plants under stress, but several questions still need to be answered. The present review is focused specifically on the importance of NO as Cd stress modulator in crop plants.
► Cadmium, a toxic heavy metal pollutant, limits the crops productivity worldwide. ► NO functions as cell signaling molecule and also involved in regulation of stress. ► Role of NO is also emerging in providing protection against Cd-induced toxicity. ► Exogenous NO addition induces decrease in Cd accumulation in plants. ► Plants possess efficient antioxidant defense systems against oxidative stress damages.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Shiga-like toxin-producing Escherichia coli (STEC) is a well-known cause of foodborne acute diarrheic diseases, especially in children and the elderly. The potentially fatal complications associated ...with toxin production range from bloody diarrhea and ischemic colitis to kidney failure, hemolytic-uremic syndrome (HUS), and colon perforation. Here, we describe a case and literature review of STEC-induced colitis, highlighting the clinical features and the necessary tools for the best diagnostic approach and management. Facing challenging differential diagnosis, ranging from ischemic colitis and inflammatory bowel disease to infectious processes due to a pathogenic or opportunistic agent, we conducted a step-by-step exploration. Following bacteriological investigation, imagistic screening, and colonoscopy, we ruled out some of the initial suppositions and reached a final diagnosis, while also considering the pathological results. Although antibiotics are not indicated in this pathology, our patient did receive antibiotics, given the risk of translocation and colon perforation, without any associated complications such as HUS or peritonitis. Detailed and rigorous investigations conducted by a multi-specialty team are required for prompt medical support. Coping with the symptoms and refraining from further complications are the mainstem aims of treatment.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The expression profiles of genes involved in DNA repair, namely
MtTdp1 (tyrosyl-DNA phosphodiesterase),
top1 (DNA topoisomerase I),
MtTFIIS (transcription elongation factor II-S) and
MtTFIIS-
like, ...were evaluated in
Medicago truncatula Gaertn. during seed imbibition carried out with the osmotic agent polyethylene glycol (PEG6000, 100
g/L). The use of PEG6000 resulted in delayed water up-take by seeds, and reduced levels of oxidative DNA damage, measured in terms of 7,8-dihydro-8-oxoguanine (8-oxo-dG) were observed compared to seeds imbibed with water. The prolonged exposure to PEG6000 caused an increase in DNA oxidative damage; after 24
h of treatment with the osmotic agent, the estimated amount of 8-oxo-dG was 1.25-fold higher compared to the value detected in seeds imbibed with water. Three days after imbibition, consistent cell damage and reactive oxygen species (ROS) production were also detected in radicles emerging from the PEG-treated seeds. All of the tested genes were known to be up-regulated during seed imbibition, with the highest transcript levels accumulating at approximately 8–12
h of rehydration. Exposure to PEG6000 caused a delayed up-regulation of
MtTdp1α and
MtTdp1β genes, with transcript peaks occurring at 12–24
h, when the highest levels of DNA damage were also recorded. For the
top1,
MtTFIIS and
MtTFIIS-like genes, different expression profiles were observed in response to PEG6000. The possible roles of these genes in the repair response activated during seed imbibition are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK
Phytic acid (PA) is a strong anti-nutritional factor with a key antioxidant role in countering reactive oxygen species. Despite the potential benefits of
(
) mutants, the reduction of PA causes ...pleiotropic effects, e.g., reduced seed germination and viability loss related to seed ageing. The current study evaluated a historical series of naturally aged seeds and showed that
seeds aged faster as compared to wildtype. To mimic natural ageing, the present study set up accelerated ageing treatments at different temperatures. It was found that incubating the seeds at 57 °C for 24 h, the wildtype germinated at 82.4% and
at 40%. The current study also hypothesized two possible solutions to overcome these problems: (1) Classical breeding was used to constitute synthetic populations carrying the
mutation, with genes pushing anthocyanin accumulation in the embryo (R-navajo allele). The outcome showed that the presence of R-navajo in the
genotype was not able to improve the germinability (-20%), but this approach could be useful to improve the germinability in non-mutant genotypes (+17%). (2) In addition, hydropriming was tested on
and wildtype seeds, and germination was improved by 20% in
, suggesting a positive role of seed priming in restoring germination. Moreover, the data highlighted metabolic differences in the metabolome before and after hydropriming treatment, suggesting that the differences in germination could also be mediated by differences in the metabolic composition induced by the mutation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Seed germination is a critical parameter for the successful development of sustainable agricultural practices. While seed germination is impaired by environmental constraints emerging from the ...climate change scenario, several types of simple procedures, known as priming, can be used to enhance it. Seed priming is defined as the process of regulating seed germination by managing a series of parameters during the initial stages of germination. Hydropriming is a highly accessible and economic technique that involves soaking of seeds in water followed by drying. Biopriming refers to the inoculation of seeds with beneficial microorganism. The present study aims to investigate whether hydropriming and biopriming could enhance seed germination. Thereby, the germination of
seeds exposed to hydropriming and/or
spp. isolates was monitored for two-weeks. The seeds were sown in trays containing two types of in situ agricultural soils collected from Northern India (Karsara, Varanasi). This region is believed to be contaminated by solid waste from a nearby power plant. Phenotypic parameters had been monitored and compared to find the most appropriate combination of treatments. Additionally,
RT-PCR was used to evaluate the expression levels of specific genes used as molecular indicators of seed quality. The results show that, while hydropriming significantly enhanced seed germination percentage, biopriming resulted in improved seedling development, represented by increased biomass rather than seedling length. At a molecular level, this is reflected by the upregulation of genes involved in DNA damage repair and antioxidant defence. In conclusion, hydropriming and biopriming are efficient to improve seed germination and seedling establishment in soils collected from damaged sites of Northern India; this is reflected by morphological parameters and molecular hallmarks of seed quality.
Plant-pathogen interaction is an inexhaustible source of information on how to sustainably control diseases that negatively affect agricultural production.
is a root-knot nematode (RKN), representing ...a pest for many crops, including tomato (
). RKNs are a global threat to agriculture, especially under climate change, and RNA technologies offer a potential alternative to chemical nematicides. While endogenous microRNAs have been identified in both
and
, and their roles have been related to the regulation of developmental changes, no study has investigated the miRNAs cross-kingdom transfer during this interaction.
Here, we propose a bioinformatics pipeline to highlight potential miRNA-dependent cross-kingdom interactions between tomato and
.
The obtained data show that nematode miRNAs putatively targeting tomato genes are mostly related to detrimental effects on plant development and defense. Similarly, tomato miRNAs putatively targeting
biological processes have negative effects on digestion, mobility, and reproduction. To experimentally test this hypothesis, an
feeding assay was carried out using sly-miRNAs selected from the bioinformatics approach. The results show that two tomato miRNAs (sly-miRNA156a, sly-miR169f) soaked by juvenile larvae (J2s) affected their ability to infect plant roots and form galls. This was also coupled with a significant downregulation of predicted target genes (
), as revealed by a qRT-PCR analysis.
Therefore, the current study expands the knowledge related to the cross-kingdom miRNAs involvement in host-parasite interactions and could pave the way for the application of exogenous plant miRNAs as tools to control nematode infection.
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