Targeted expression of bgl23-D, a dominant-negative allele of ATCSLD5, affects cytokinesis of guard mother cells and exine formation of pollen in Arabidopsis thaliana.

MAIN CONCLUSION: Targeted expression of bgl23-D, a dominant-negative allele of ATCSLD5, is a useful genetic approach for functional analysis of ATCSLDs in specific cells and tissues in plants. Stomata are key cellular structures for gas and water exchange in plants and their development is influenced by several genes. We found the A. thaliana bagel23-D (bgl23-D) mutant showing abnormal bagel-shaped single guard cells. The bgl23-D was a novel dominant mutation in the A. thaliana cellulose synthase-like D5 (ATCSLD5) gene that was reported to function in the division of guard mother cells. The dominant character of bgl23-D was used to inhibit ATCSLD5 function in specific cells and tissues. Transgenic A. thaliana expressing bgl23-D cDNA with the promoter of stomata lineage genes, SDD1, MUTE, and FAMA, showed bagel-shaped stomata as observed in the bgl23-D mutant. Especially, the FAMA promoter exhibited a higher frequency of bagel-shaped stomata with severe cytokinesis defects. Expression of bgl23-D cDNA in the tapetum with SP11 promoter or in the anther with ATSP146 promoter induced defects in exine pattern and pollen shape, novel phenotypes that were not shown in the bgl23-D mutant. These results indicated that bgl23-D inhibited unknown ATCSLD(s) that exert the function of exine formation in the tapetum. Furthermore, transgenic A. thaliana expressing bgl23-D cDNA with SDD1, MUTE, and FAMA promoters showed enhanced rosette diameter and increased leaf growth. Taken together, these findings suggest that the bgl23-D mutation could be a helpful genetic tool for functional analysis of ATCSLDs and manipulating plant growth.

Estimation of life history parameters for river catfish Eutropiichthys vacha: insights from multi-models for sustainable management.

The river catfish, Eutropiichthys vacha is a vital protein source for rural communities and has high commercial value, but understanding its life history and management strategies reveals major inadequacies and ambiguities in the riverine ecosystems. Consequently, this study employs multi-models to analyze the life history parameters of E. vacha in the Ganges River (northwestern Bangladesh) from January to December, 2020. The total length (TL) and body weight (BW) of 362 individuals (male = 170, female = 192) were measured by a measuring board and a digital weighing balance, respectively. The overall sex ratio (male: female) was 1.0: 1.13 and did not oscillate statistically from the standard 1:1 ratio (p > 0.05). The TL varied from 6.7-19.2 cm for males and 6.3-19.0 cm for females. The length-frequency distributions (LFDs) revealed females outnumbered in 8.0-9.99 cm TL whereas males in 7.0-7.99 cm TL. The slope (b) of the length-weight relationship (TL vs. BW) for both sexes (b = 2.87) was substantially lower than isometry, specifying negative allometric growth pattern for E. vacha. Sex-specific relative (K R ) and Fulton's (K F ) condition analysis revealed better state of well-being of males than females. Only K F exhibited significant correlation with both BW and TL, hence making it ideal condition for predicting the fitness of E. vacha in this river. Moreover, the relative weight (W R ) suggests an imbalanced habitat for females with higher abundance of predators but suitable for males. The form factor (a 3.0 ) was 0.0062 and 0.0065, whereas the size at first maturity (L m ) and mean natural mortality (M W ) were 11.38 and 11.27 cm TL and 1.29 and 1.28 year-1 for the respective sexes. Besides, the calculated mean optimum catchable length (L opt ) was 13.58 and 13.09 cm TL for each sex. These findings will be crucial for further studies and to recommend appropriate strategy for the sustainable management of E. vacha in the Ganges River and adjacent watersheds.

Expression analysis of plant intracellular Ras-group related leucine-rich repeat proteins (PIRLs) in Arabidopsis thaliana.

Arabidopsis thaliana contains a family of nine genes known as plant intracellular Ras-group related leucine-rich repeat (LRR) proteins (PIRLs). These are structurally similar to animals and fungal LRR proteins and play important roles in developmental pathways. However, to date, no detailed tissue-specific expression analysis of these PIRLs has been performed. Therefore, in this study, we generated promoter:GUS transgenic plants for the nine A. thaliana PIRL genes and identified their expression patterns in seedlings and floral organs at different developmental stages. Most PIRL members showed expression in the root apical region and in the vascular tissue of primary and lateral roots. Shoot apex-specific expression was recorded for PIRL1 and PIRL8. Furthermore, PIRL1, PIRL3, PIRL5, PIRL6, and PIRL7 showed distinct expression patterns in flowers, especially in pollen and anthers. In addition, co-expression network analysis identified cases where PIRLs were co-expressed with other genes known to have specific functions related to growth and development. Taken together, the tissue-specific expression patterns of PIRL genes improve our understanding of the functions of this gene family in plant growth and development.

Molecular identification and biological control of Ralstonia solanacearum from wilt of papaya by natural compounds and Bacillus subtilis: An integrated experimental and computational study.

Ralstonia solanacearum is a harmful pathogen that causes severe wilt disease in several vegetables. In the present study, we identified R. solanacearum from wilt of papaya by 16S rRNA PCR amplification. Virulence ability of R. solanacearum was determined by amplification of approximately 1500 bp clear band of hrpB gene. Further, in-vitro seed germination assay showed that R. solanacearum reduced the germination rate up to 26.21%, 34% and 33.63% of cucumber, bottle guard and pumpkin seeds, respectively whereas shoot and root growth were also significantly decreased. Moreover, growth inhibition of R. solanacearum was recorded using antibacterial compound from medicinal plant and antagonistic B. subtilis. Petroleum ether root extract of Rauvolfia serpentina showed highest 22 ± 0.04 mm diameter of zone of inhibition where methanolic extract of Cymbopogon citratus and ethanolic extract of Lantana camara exhibited 20 ± 0.06 mm and 20 ± 0.01 mm zone of inhibition against R. solanacearum, respectively. In addition, bioactive compounds of B. subtilis inhibited R. solanacearum growth by generating 17 ± 0.09 mm zone of inhibition. To unveil the inhibition mechanism, we adopted chemical-protein interaction network and molecular docking approaches where we found that, rutin from C. citratus interacts with citrate (Si)-synthase and dihydrolipoyl dehydrogenase of R. solanacearum with binding affinity of -9.7 kcal/mol and -9.5 kcal/mol while quercetin from B. subtillis interacts with the essential protein F0F1 ATP synthase subunit alpha of the R. solancearum with binding affinity of -6.9 kcal/mol and inhibit the growth of R. solanacearum. Our study will give shed light on the development of eco-friendly biological control of wilt disease of papaya.

Stomatal development and genetic expression in Arabidopsis thaliana L.

Stomata are turgor-driven microscopic epidermal valves of land plants. The controlled opening and closing of the valves are essential for regulating the gas exchange and minimizing the water loss and eventually regulating the internal temperatures. Stomata are also a major site of pathogen/microbe entry and plant defense system. Maintaining proper stomatal density, distribution, and development are pivotal for plant survival. Arabidopsis is a model plant to study molecular basis including signaling pathways, transcription factors, and key components for the growth and development of specific organs as well as the whole plant. It has intensively been studied and found out the driver for the development and patterning of stomata. In this review, we have explained how the MAPK signaling cascade is controlled by TOO MANY MOUTHS (TMM) receptor-like protein and the Erecta (ER) receptor-like kinase family. We have also summarized how this MAPK cascade affects primary transcriptional regulators to finally activate the main three basic Helix-Loop-Helix (bHLH) principal transcription factors, which are required for the development and patterning of stomata. Moreover, regulatory activity and cellular connections of polar proteins and environmentally mediated ligand-receptor interactions in the stomatal developmental pathways have extensively been discussed in this review.

Clinical manifestations and socio-demographic status of COVID-19 patients during the second-wave of pandemic: A Bangladeshi experience.

BACKGROUND: Bangladesh is a densely populated country with a substandard healthcare system and a mediocre economic framework. Due to the enormous number of people who have been unaware until now, the development of COVID-19's second-wave infection has become a severe threat. The present investigation aimed to characterize the clinical and socio-demographic characteristics of COVID-19 in Bangladesh. METHODS: A cross-sectional analysis was carried out from all the other COVID-19 patients and confirmed by RT-PCR undergoing a specialized COVID-19 hospital. From March 1 to April 15, 2021, a total of 1326 samples were collected. Samples were only obtained from non-critical COVID-19 patients as critically ill patients required emergency intensive care medications. Then, from April 17 to May 03, 2021, SARS-CoV-2 infection and clinical assessment was performed based on interim guidelines from the WHO. The diagnosis was conducted through RT-PCR. Later, identifying the symptomatic and asymptomatic patient based on checking the Clinical Observation Form (COF). The patients filled the COF form. Finally, statistical analyses were done using the SPSS 20 statistical program. RESULTS: In this investigation, a total of 326 patients were diagnosed as COVID-19 positive. Among them, approximately 19.02% (n = 62) were asymptomatic, and 80.98% (n = 264) were symptomatic. Here, the finding shows that the occurrence of this infection was varied depending on age, sex, residence, occupation, smoking habit, comorbidities, etc. However, Males (60.12%) were more affected than females (39.88%), and, surprisingly, this pandemic infected both urban and rural residents almost equally (urban = 50.92%; rural = 49.08%). Approximately 19% of the asymptomatic and 62% of symptomatic cases had at least one comorbid disorder. Interestingly, an unexpected result was exhibited in the case of smokers, where non-smokers were more affected than smokers. The study indicates community transmission of COVID 19, where people were highly infected at their occupations (35.58%), at houses (23.93%) and by traveling (12.88%). Noteworthy, according to this report, a large number (19.33%) of individuals did not know exactly how they were contaminated with SARS-CoV-2. Patients were most commonly treated by an antibiotic 95.09%, followed in second by corticosteroid 46.01%. Anti-viral drugs, remdesivir, and oxygenation are also needed for other patients. Among those, who were being treated, approximately 69.33% were isolated at home, 27.91% were being treated at dedicated COVID-19 hospitals. Finally, 96.63% were discharged without complications, and 0.03% has died. CONCLUSION: This investigation concludes that males became more infected than females. Interestingly, both urban and rural people became nearly equally infected. It noticed community transmission of SARS-CoV-2, where people were highly infected at their workplaces. A higher rate of silent transmission indicates that more caution is needed to identify asymptomatic patients. Most of the infected people were isolated at home whereas nearly one-fourth were treated at hospitals. Clinically, antibiotics were the most widely used treatment. However, the majority of the patients were discharged without complications. The current investigation would be helpful to understand the clinical manifestations and socio-demographic situations during the second wave of the COVID-19 pandemic in Bangladesh.