A newly evolved rice-specific gene JAUP1 regulates jasmonate biosynthesis and signalling to promote root development and multi-stress tolerance

Root architecture and function are critical for plants to secure water and nutrient supply from the soil, but environmental stresses alter root development. The phytohormone jasmonic acid (JA) regulates plant growth and responses to wounding and other stresses, but its role in root development for adaptation to environmental challenges had not been well investigated. We discovered a novel JA Upregulated Protein 1 gene (JAUP1) that has recently evolved in rice and is specific to modern rice accessions. JAUP1 regulates a self-perpetuating feed-forward loop to activate the expression of genes involved in JA biosynthesis and signalling that confers tolerance to abiotic stresses and regulates auxin-dependent root development. Ectopic expression of JAUP1 alleviates abscisic acid- and salt-mediated suppression of lateral root (LR) growth. JAUP1 is primarily expressed in the root cap and epidermal cells (EPCs) that protect the meristematic stem cells and emerging LRs. Wound-activated JA/JAUP1 signalling promotes crosstalk between the root cap of LR and parental root EPCs, as well as induces cell wall remodelling in EPCs overlaying the emerging LR, thereby facilitating LR emergence even under ABA-suppressive conditions. Elevated expression of JAUP1 in transgenic rice or natural rice accessions enhances abiotic stress tolerance and reduces grain yield loss under a limited water supply. We reveal a hitherto unappreciated role for wound-induced JA in LR development under abiotic stress and suggest that JAUP1 can be used in biotechnology and as a molecular marker for breeding rice adapted to extreme environmental challenges and for the conservation of water resources.

Expression of Chitinase and shRNA Gene Exhibits Resistance to Fungi and Virus

With the increasing global population, saving crops from diseases caused by different kinds of bacteria, fungi, viruses, and nematodes is essential. Potato is affected by various diseases, destroying many crops in the field and storage. In this study, we developed potato lines resistant to fungi and viruses, Potato Virus X (PVX) and Potato Virus Y (PVY), by inoculating chitinase for fungi and shRNA designed against the mRNA of the coat protein of PVX and PVY, respectively. The construct was developed using the pCAMBIA2301 vector and transformed into AGB-R (red skin) potato cultivar using Agrobacterium tumefaciens. The crude protein extract of the transgenic potato plant inhibited the growth of Fusarium oxysporum from ~13 to 63%. The detached leaf assay of the transgenic line (SP-21) showed decreased necrotic spots compared to the non-transgenic control when challenged with Fusarium oxysporum. The transgenic line, SP-21, showed maximum knockdown when challenged with PVX and PVY, i.e., 89 and 86%, while transgenic line SP-148 showed 68 and 70% knockdown in the PVX- and PVY-challenged conditions, respectively. It is concluded from this study that the developed transgenic potato cultivar AGB-R showed resistance against fungi and viruses (PVX and PVY).

Soil microbiome feedback to climate change and options for mitigation

Microbes are a critical component of soil ecosystems, performing crucial functions in biogeochemical cycling, carbon sequestration, and plant health. However, it remains uncertain how their community structure, functioning, and resultant nutrient cycling, including net GHG fluxes, would respond to climate change at different scales. Here, we review global and regional climate change effects on soil microbial community structure and functioning, as well as the climate-microbe feedback and plant-microbe interactions. We also synthesize recent studies on climate change impacts on terrestrial nutrient cycles and GHG fluxes across different climate-sensitive ecosystems. It is generally assumed that climate change factors (e.g., elevated CO₂ and temperature) will have varying impacts on the microbial community structure (e.g., fungi-to-bacteria ratio) and their contribution toward nutrient turnover, with potential interactions that may either enhance or mitigate each other's effects. Such climate change responses, however, are difficult to generalize, even within an ecosystem, since they are subjected to not only a strong regional influence of current ambient environmental and edaphic conditions, historical exposure to fluctuations, and time horizon but also to methodological choices (e.g., network construction). Finally, the potential of chemical intrusions and emerging tools, such as genetically engineered plants and microbes, as mitigation strategies against global change impacts, particularly for agroecosystems, is presented. In a rapidly evolving field, this review identifies the knowledge gaps complicating assessments and predictions of microbial climate responses and hindering the development of effective mitigation strategies.

Oral Class I and III antiarrhythmic drugs for maintaining sinus rhythm after catheter ablation of atrial fibrillation

BACKGROUND

Recurrence of atrial tachyarrhythmias (ATa) following catheter ablation for atrial fibrillation (AF) is a common problem. Antiarrhythmic drugs have been used shortly after ablation in an attempt to maintain sinus rhythm, particularly Class I and III agents. However, it still needs to be established if the use of Class I or III antiarrhythmic medications, or both, reduce the risk of recurrence of ATa.

OBJECTIVES

To assess the effects of oral Class I and III antiarrhythmic drugs versus control (standard medical therapy without Class I or III antiarrhythmics, or placebo) for maintaining sinus rhythm in people undergoing catheter ablation for AF.

SEARCH METHODS

We systematically searched CENTRAL, MEDLINE, Embase, Web of Science Core Collection, and two clinical trial registers without restrictions on language or date to 5 August 2022.

SELECTION CRITERIA

We sought published, unpublished, and ongoing parallel-design, randomised controlled trials (RCTs) involving adult participants undergoing ablation for AF, with subsequent comparison of Class I and/or III antiarrhythmic use versus control (standard medical therapy or non-Class I and/or III antiarrhythmic use).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane and performed meta-analyses with risk ratios (RR) and Peto odds ratios (Peto OR). Our primary outcomes were recurrence of atrial tachyarrhythmias; adverse events: thromboembolic events; adverse events: myocardial infarction; adverse events: new diagnosis of heart failure; and adverse events: requirement for one or more hospitalisations for atrial tachyarrhythmia. Our secondary outcomes were: all-cause mortality; and requirement for one or more repeat ablations. Where possible, we performed comparison analysis by Class I and/or III antiarrhythmic and divided follow-up periods for our primary outcome. We performed comprehensive assessments of risk of bias and certainty of evidence applying the GRADE methodology.

MAIN RESULTS

We included nine RCTs involving a total of 3269 participants. Participants were on average 59.3 years old; 71.0% were male; and 72.9% and 27.4% had paroxysmal and persistent AF, respectively. Class I and/or III antiarrhythmics may reduce recurrence of ATa at 0 to 3 months postablation (risk ratio (RR) 0.74, 95% confidence interval (CI) 0.59 to 0.94, 8 trials, 3046 participants, low-certainty evidence) and likely reduce recurrence at > 3 to 6 months, our a priori primary time point (RR 0.85, 95% CI 0.78 to 0.93, 5 trials, 2591 participants, moderate-certainty evidence). Beyond six months the evidence is very uncertain, and the benefit of antiarrhythmics may not persist (RR 1.14, 95% CI 0.84 to 1.55, 4 trials, 2244 participants, very low-certainty evidence). The evidence suggests that Class I and/or III antiarrhythmics may not increase the risk of thromboembolic events, myocardial infarction, all-cause mortality, or requirement for repeat ablation, at 0 to 3, > 3 to 6, and > 6 months (where data were available; low- to very low-certainty evidence). The use of Class I and/or III antiarrhythmics postablation likely reduces hospitalisations for ATa by approximately 57% at 0 to 3 months (RR 0.43, 95% CI 0.28 to 0.64, moderate-certainty evidence). No data were available beyond three months. No data were available on new diagnoses of heart failure. Fewer data were available for Class I and III antiarrhythmics individually. Based on only one and two trials (n = 125 to 309), Class I antiarrhythmics may have little effect on recurrence of ATa at 0 to 3, > 3 to 6, and > 6 months (RR 0.88, 95% CI 0.64 to 1.20, 2 trials, 309 participants; RR 0.54, 95% CI 0.25 to 1.19, 1 trial, 125 participants; RR 0.87, 95% CI 0.57 to 1.32, 1 trial, 125 participants; low-certainty evidence throughout); requirement for hospitalisation for ATa at 0 to 3 months (low-certainty evidence); or requirement for repeat ablation at 0 to 3 months (low-certainty evidence). No data were available for thromboembolic events, myocardial infarction, new diagnosis of heart failure, or all-cause mortality at any time points, or hospitalisation or repeat ablation beyond three months. Class III antiarrhythmics may have little effect on recurrence of ATa at up to 3 months and at > 3 to 6 months (RR 0.76, 95% CI 0.50 to 1.16, 4 trials, 599 participants, low-certainty evidence; RR 0.82, 95% CI 0.62 to 1.09, 2 trials, 318 participants, low-certainty evidence), and beyond 6 months one trial reported a possible increase in recurrence of ATa (RR 1.95, 95% CI 1.29 to 2.94, 1 trial, 112 participants, low-certainty evidence). Class III antiarrhythmics likely reduce hospitalisations for ATa at 0 to 3 months (RR 0.40, 95% CI 0.26 to 0.63, moderate-certainty evidence), and may have little effect on all-cause mortality (low- to very low-certainty evidence). The effect of Class III antiarrhythmics on thromboembolic events and requirement for repeat ablation was uncertain (very low-certainty evidence for both outcomes). No data were available for myocardial infarction or new diagnosis of heart failure at any time point, outcomes other than recurrence beyond 6 months, or for hospitalisation and repeat ablation > 3 to 6 months. We assessed the majority of included trials as at low or unclear risk of bias. One trial reported an error in the randomisation process, raising the potential risk of selection bias; most of the included trials were non-blinded; and two trials were at high risk of attrition bias.

AUTHORS' CONCLUSIONS

We found evidence to suggest that the use of Class I and/or III antiarrhythmics up to 3 months after ablation is associated with a reduced recurrence of ATa 0 to 6 months after ablation, which may not persist beyond 6 months, and an immediate reduction in hospitalisation for ATa 0 to 3 months after ablation. The evidence suggests there is no difference in rates of all-cause mortality, thromboembolic events, or myocardial infarction between Class I and/or III antiarrhythmics versus control.

Molecular and Biochemical Characterization of Cotton Epicuticular Wax in Defense Against Cotton Leaf Curl Disease

BACKGROUND

Gossypium arboreumis resistant to Cotton leaf curl Burewala virus and its cognate Cotton leaf curl Multan beta satellite (CLCuBuV and CLCuMB). However, the G. arboreum wax deficient mutant (GaWM3) is susceptible to CLCuV. Therefore, epicuticular wax was characterized both quantitatively and qualitatively for its role as physical barrier against whitefly mediated viral transmission and co-related with the titer of each viral component (DNA-A, alphasatellite and betasatellite) in plants.

OBJECTIVES

The hypothesis was the CLCuV titer in cotton is dependent on the amount of wax laid down on plant surface and the wax composition.

RESULTS

Analysis of the presence of viral genes, namely alphasatellite, betasatellite and DNA-A, via real-time PCR in cotton species indicated that these genes are detectable in G. hirsutum, G. harknessii and GaWM3, whereas no particle was detected in G. arboreum. Quantitative wax analysis revealed that G. arboreum contained 183 μg.cm^-2 as compared to GaWM3 with only 95 μg.cm^-2. G. hirsutum and G. harknessii had 130 μg.cm^-2 and 146 μg.cm^-2, respectively. The GCMS results depicted that Lanceol, cis was 45% in G. harknessii. Heptadecanoic acid was dominant in G. arboreum with 25.6%. GaWM3 had 18% 1,2,-Benenedicarboxylic acid. G. hirsutum contained 25% diisooctyl ester. The whitefly feeding assay with Nile Blue dye showed no color in whiteflies gut fed on G. arboreum. In contrast, color was observed in the rest of whiteflies.

CONCLUSIONS

From results, it was concluded that reduced quantity as well as absence of (1) 3-trifluoroacetoxytetradecane, (2) 2-piperidinone,n-|4-bromo-n-butyl|, (3) 4-heptafluorobutyroxypentadecane, (4) Silane, trichlorodocosyl-, (5) 6- Octadecenoic acid, methyl ester, and (6) Heptadecanoicacid,16-methyl-,methyl ester in wax could make plants susceptible to CLCuV, infested by whiteflies.

Chloroplast localization of Cry1Ac and Cry2A protein--an alternative way of insect control in cotton

BACKGROUND

Insects have developed resistance against Bt-transgenic plants. A multi-barrier defense system to weaken their resistance development is now necessary. One such approach is to use fusion protein genes to increase resistance in plants by introducing more Bt genes in combination. The locating the target protein at the point of insect attack will be more effective. It will not mean that the non-green parts of the plants are free of toxic proteins, but it will inflict more damage on the insects because they are at maximum activity in the green parts of plants.

RESULTS

Successful cloning was achieved by the amplification of Cry2A, Cry1Ac, and a transit peptide. The appropriate polymerase chain reaction amplification and digested products confirmed that Cry1Ac and Cry2A were successfully cloned in the correct orientation. The appearance of a blue color in sections of infiltrated leaves after 72 hours confirmed the successful expression of the construct in the plant expression system. The overall transformation efficiency was calculated to be 0.7%. The amplification of Cry1Ac-Cry2A and Tp2 showed the successful integration of target genes into the genome of cotton plants. A maximum of 0.673 μg/g tissue of Cry1Ac and 0.568 μg/g tissue of Cry2A was observed in transgenic plants. We obtained 100% mortality in the target insect after 72 hours of feeding the 2nd instar larvae with transgenic plants. The appearance of a yellow color in transgenic cross sections, while absent in the control, through phase contrast microscopy indicated chloroplast localization of the target protein.

CONCLUSION

Locating the target protein at the point of insect attack increases insect mortality when compared with that of other transgenic plants. The results of this study will also be of great value from a biosafety point of view.

Characteristics of effective clinical teachers identified by dental students: a qualitative study

This qualitative research study identified criteria for clinical teacher quality preferences as perceived by dental students. Third and fourth year dental students at New York University College of Dentistry were given a two question, open-ended survey asking what qualities they liked most and least in a clinical teacher. Responses were collected until data saturation was achieved. A total of 157 respondents provided a total of 995 written comments. Descriptive words within the responses were coded and grouped into key words, according to similar relationships, and further refined into 17 defined categories. Three core themes, Character, Competence and Communication, emerged from these 17 categories, which were validated according to specific references found in the existing educational literature. 'Character' comprised nine of the 17 defined categories: (caring, motivation, empathy, patience, professionalism, available, fairness, happiness, patient-centred) and yielded 59.1% of total student responses; 'Competence' consisted of five categories: knowledgeable, expertise, efficient, skilful, effective (29.2%); and 'Communication' represented the remaining three categories: feedback, approachable and interpersonal communication (11.7%). Positive and negative responses related to the defined category of caring were cited by 59.2% of all students. Motivation was the next highest category, cited by 45.9% of students. Non-cognitive attributes, especially those in the Character theme, comprised the majority of student comments. Because students' perceptions are so critical to understanding clinical teaching effectiveness in dental education, these findings can be used to develop assessments to measure clinical teaching effectiveness, to create criteria for the hiring and promotion of clinical faculty and to plan faculty development programming.

Management of Diarrhea in Under-fives at Home and Health Facilities in Kashmir

BACKGROUND

Diarrheal disease forms one of the two major killer diseases in children under five years of age in the developing world. There are inherent cultural practices for management of diarrhea at the domestic level. Also, the treatment practices at health centers vary, with inappropriate use of antibiotics, and iv fluids observed commonly, while ORS is less frequently used.

METHODOLOGY

Cross sectional study was carried out using pretested interview schedule between January and December 2006, in villages of Kashmir Valley.

RESULTS

The ORS use rate is low (24.4% and 8.4%) respectively in past and current episode. Cultural practices include harmful ones like starving to overcome the episode. The rate of Antibiotic use is higher with 77.9%.

CONCLUSION

Kashmir valley faces the same problems in effective diarrhea management as in other developing regions of India and the world, viz. less ORS use, high antibiotic use and harmful cultural practices like giving bowel rest.

Prevalence of Diarrhoeal Disease, its Seasonal and Age Variation in under- fives in Kashmir, India

BACKGROUND

Diarrhoeal disease forms one of the two major killer diseases in children under five years of age in the developing world. Data on the prevalence and related factors of diarrhea in Kashmir valley is quite scanty. Thus this study was carried out to find the burden of diarrhoeal disease and the effect of a temperate climate (as compared to a tropical one in rest of India) on the pattern of diarrhoeal disease in Kashmir valley.

METHODS

Cross sectional study was carried out using pretested interview schedule.

RESULTS

Overall period (last 15 days) and point (24 hrs) prevalence rates of diarrhoeal diseases among children under age of 5 years were calculated which came to the order of (25.2%) and (9.3%) respectively. Prevalence of diarrhoea decreased significantly with increased age and in summer months.

CONCLUSION

The burden of diarrhoeal disease in Kashmir is quite high, like most places in the developing world. The age pattern, and seasonal pattern of diarrhoeal disease also resembles that found in studies across India and the developing world.

Fluorinated colchicinoids: antitubulin and cytotoxic properties

The synthesis of B-ring and C-ring trifluoroacetamide-substituted colchicinoids and fluoro-substituted colchicineethylamides is presented. The B-ring trifluoroacetamido-substituted analogues exhibit moderate enhancement of potency compared to the nonfluorinated analogues for tubulin assembly inhibition and cytotoxicity toward two wild type cell lines. The C-ring substituted fluoroethylamides have reduced relative potencies in the same systems due to the strong electron-withdrawing effect of the fluoro derivatives. The fluoro colchicinoids are much more cytotoxic toward drug-resistant cell lines than to the wild type cell lines. Their enhanced potency is probably due to an effect of the fluoro moiety on functions specific to resistant cells and/or their higher hydrophobicity that may result in higher intracellular drug content. This finding may suggest the application of designed fluorinated anticancer drugs to overcome acquired resistance which may develop after several regiments of treatment with a nonfluorinated chemotherapeutic agent.

Chemistry of colchicine

Chemical structures of colchicine and related analogs, including allo-compounds with a six-membered ring, are presented here with correct absolute configurations, showing the natural representatives as a S-atropisomers. Spectral data, synthesis, biosynthesis, and metabolism of colchicine are discussed. Structural requirements required for these compounds to inhibit polymerization of tubulin and binding of radiolabeled colchicine in vitro are presented.

N-acetylcolchinol O-methyl ether and thiocolchicine, potent analogs of colchicine modified in the C ring. Evaluation of the mechanistic basis for their enhanced biological properties

Two colchicine analogs with modifications only in the C ring are better inhibitors than colchicine of cell growth and tubulin polymerization. Radiolabeled thiocolchicine (with a thiomethyl instead of a methoxy group at position C-10) and N-acetylcolchinol O-methyl ether (NCME) (with a methoxy-substituted benzenoid instead of the methoxy-substituted tropone C ring) were prepared for comparison with colchicine. Scatchard analysis indicated a single binding site with KD values of 1.0-2.3 microM. Thiocolchicine was bound 2-4 times as rapidly as colchicine, but the activation energies of the reactions were nearly identical (18 kcal/mol for colchicine, 20 kcal/mol for thiocolchicine). NCME bound to tubulin in a biphasic reaction. The faster phase was 60 times as fast as colchicine binding at 37 degrees C, and a substantial reaction occurred at 0 degrees C. The rate of the faster phase of NCME binding changed relatively little as a function of temperature, so the activation energy was only 7.0 kcal/mol. Dissociation reactions were also evaluated, and at 37 degrees C the half-lives of the tubulin-drug complexes were 11 min for NCME, 24 h for thiocolchicine, and 27 h for colchicine. Relative dissociation rates as a function of temperature varied little among the drug complexes. Activation energies for the dissociation reactions were 30 kcal/mol for thiocolchicine, 27 kcal/mol for NCME, and 24 kcal/mol for colchicine. Comparison of the activation energies of association and dissociation yielded free energies for the binding reactions of -20 kcal/mol for NCME, -10 kcal/mol for thiocolchicine, and -6 kcal/mol for colchicine. The greater effectiveness of NCME and thiocolchicine as compared with colchicine in biological assays probably derives from their more rapid binding to tubulin and the lower free energies of their binding reactions.

The ontogeny of the rabbit brain glucose transporter

We investigated the presence of three specific types of glucose transporters (GT) within the rabbit central nervous system during various developmental stages. Employing the Hep G2/brain-type insulin-insensitive and the insulin-responsive (IRGT; adipocyte/skeletal muscle type) GT antibody and cDNA, we studied protein and mRNA within the whole brain (25-, 27-, and 30-day-old fetus; 1-, 5-, 10-day-old neonate; and adult), using cultured neuronal and glial cells, by Western and Northern blot analysis. Similarly, using the insulin-insensitive human fetal skeletal muscle-type (GLUT-3) GT cDNA, we characterized this mRNA by Northern blot analysis. Additional confirmation of cell specificity was sought by performing immunohistochemical staining on the neuronal and glial cells to detect the specific type of GT protein. We observed a developmental regulation of brain-type GT within the whole brain, the peak abundance of protein and mRNA occurring in the adult, followed next by the fetus. No IRGT was detected within the whole brain at any stage of development. Contrary to the brain-type GT mRNA, GLUT-3 mRNA was found to be most abundant in the 10-day-old neonate and adult, followed next by the early neonate, with little in the fetus. Within isolated brain cell cultures, the mRNAs for the brain- and GLUT-3-types of GTs were abundantly present within glial cells, with considerably lesser amounts noted within the neurons. IRGT, on the other hand, revealed rather weak mRNA bands in both glial and neuronal cells. Western blotting revealed a brain type of GT protein within the glial cells alone; the neuronal cells for the most part were devoid of both the brain-type and the IRGT proteins. Further immunohistochemical staining confirmed the definite presence of the brain-type GT within the glial cells, with slight immunoreactivity observed within the neurons. Additionally, no significant IRGT immunoreactivity was observed within either cell type. We did not study the GLUT-3 type of immunoreactivity within neurons and glia. We conclude that both the Hep G2/brain and the GLUT-3 types, and not the IRGT, are developmentally regulated within the whole brain. Further, the Hep G2/brain and the GLUT-3 types of GTs are distinctly present within glial cells, with none to minute amounts present within the neurons. No IRGT protein is observed within the whole brain and the two cell types. These results suggest a differential expression of specific GT types within the neuronal and glial components of the brain.

aS,7S-absolute configuration of natural (-)-colchicine and allo-congeners

The aS,7S-absolute configuration of (-)-colchicine (1) and (-)-N-acetylcolchinol methyl ether (3, NCME) suggested on the basis of 1H NMR data and negative Cotton effects at about 260 nm (EtOH) is firmly established by an X-ray analysis of urea 5, a compound derived from 3. Binding of these compounds to tubulin requires an aS-configuration of the biaryl system.

Antitubulin effects of derivatives of 3-demethylthiocolchicine, methylthio ethers of natural colchicinoids, and thioketones derived from thiocolchicine. Comparison with colchicinoids

Esterification of the phenolic group in 3-demethylthiocolchicine and exchange of the N-acetyl group with other N-acyl groups or a N-carbalkoxy group afforded many compounds which showed superior activity over the parent drug as inhibitors of tubulin polymerization and of the growth of L1210 murine leukemia cells in culture. A comparison of naturally occurring Colchicum alkaloids with thio isosters, obtained by replacing the OMe group at C(10) with a SCH3 group, showed the thio ethers to be invariably more potent in these assays. The comparison included 3-demethylthiodemecolcine prepared from 3-demethylthiocolchicine by partial synthesis. Thiation of thiocolchicine with Lawesson's reagent afforded novel thiotropolones which exhibited high antitubulin activity. Their structures are fully secured by spectral data. Colchicine and several of its analogues show good antitumor effect in mice infected with P388 lymphocytic leukemia, and all of them show high affinity for tubulin and inhibit tubulin polymerization at low concentration. Consequently, antitubulin assays with this class of compounds can serve as valuable prescreens for the initial evaluation of potential antitumor drugs.

Demethylpeceyline, A New Dimeric Indoline Alkaloid from Petchia ceylanica

A new dimeric indoline alkaloid has been isolated from the leaves of PETCHIA CEYLANICA. Its structure has been assigned as 1 on the basis of spectral studies. Its stereochemistry has been established by NOE difference measurements.

Isolation and 1H/13C-NMR Studies on 19,20-Dihydrocondylocarpine: An Alkaloid from the Leaves of Ervatamia coronaria and Alstonia scholaris

Studies on the alkaloidal constituents of the leaves of Ervatamia coronaria Stapf and Alstonia scholaris have resulted in the isolation of (20 S)-19,20-dihydrocondylocarpine which has not been previously reported from these plants. The stereochemistry at C-20 was established with the help of n. O. e. difference measurements. (13)C-NMR assignments have been made by polarisation transfer techniques.