Domain of unknown function (DUF) is a general term for many uncharacterized domains with two distinct features: relatively conservative amino acid sequence and unknown function of the domain. In the Pfam 35.0 database, 4795 (24%) gene families belong to the DUF type, yet, their functions remain to be explored. This review summarizes the characteristics of the DUF protein families and their functions in regulating plant growth and development, generating responses to biotic and abiotic stress, and other regulatory roles in plant life. Though very limited information is available about these proteins yet, by taking advantage of emerging omics and bioinformatic tools, functional studies of DUF proteins could be utilized in future molecular studies.

In plants, lesion mimic mutants (LMMs) reveal spontaneous disease-like lesions in the absence of pathogen that constitutes powerful genetic material to unravel genes underlying programmed cell death (PCD), particularly the hypersensitive response (HR). However, only a few LMMs are reported in soybean, and no related gene has been cloned until now. In the present study, we isolated a new LMM named spotted leaf-1 (spl-1) from NN1138-2 cultivar through ethyl methanesulfonate (EMS) treatment. The present study revealed that lesion formation might result from PCD and excessive reactive oxygen species (ROS) accumulation. The chlorophyll content was significantly reduced but antioxidant activities, viz., superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), as well as the malondialdehyde (MDA) contents, were detected higher in spl-1 than in the wild-type. According to segregation analysis of mutant phenotype in two genetic populations, viz., W82×spl-1 and PI378692×spl-1, the spotted leaf phenotype of spl-1 is controlled by a single recessive gene named lm1. The lm1 locus governing mutant phenotype of spl-1 was first identified in 3.15 Mb genomic region on chromosome 04 through MutMap analysis, which was further verified and fine mapped by simple sequence repeat (SSR) marker-based genetic mapping. Genetic linkage analysis narrowed the genomic region (lm1 locus) for mutant phenotype to a physical distance of ~76.23 kb. By searching against the Phytozome database, eight annotated candidate genes were found within the lm1 region. qRT-PCR expression analysis revealed that, among these eight genes, only Glyma.04g242300 showed highly significant expression levels in wild-type relative to the spl-1 mutant. However, sequencing data of the CDS region showed no nucleotide difference between spl-1 and its wild type within the coding regions of these genes but might be in the non-coding regions such as 5′ or 3′ UTR. Hence, the data of the present study are in favor of Glyma.04g242300 being the possible candidate genes regulating the mutant phenotype of spl-1. However, further validation is needed to prove this function of the gene as well as its role in PCD, which in turn would be helpful to understand the mechanism and pathways involved in HR disease resistance of soybean.

The goal of this study was to evaluate the antibacterial and cytotoxic effects of both the in vitro and in vivo plant part extracts of the medicinal plant Gynura procumbens. An effective protocol for regeneration and callus formation was developed using nodal segments and regenerated leaf explants, respectively. The highest fresh and dry weight calli were produced after four weeks of culture on Murashige and Skoog (MS) medium containing 2.0 mg/L BAP and 2.0 mg/L NAA, while the most shoots were produced on MS medium containing 1.0 mg/L BAP and 0.5 mg/L IAA. The in vitro shoots developed roots on MS media with 0.1 mg/L IBA. The antibacterial activity of extracts against various bacteria was examined to determine their significance (p < 0.05). The least significant difference (LSD) test results showed that the regenerated leaf extract had the highest antibacterial activity while the callus extract had the lowest. The minimum bactericidal concentration (MBC) and the minimum inhibitory concentration (MIC) were also established. Regenerated leaf extract had the highest toxicity and the lowest lethal concentration (LC50) value (1.21 ± 0.03 μg/mL) in a brine shrimp lethality bioassay. In contrast, callus extract had the lowest toxicity and the highest LC50 (11.09 ± 0.4 μg/mL). In addition, the in vitro cytotoxicity test results revealed that the callus and field leaf extracts had anti-cell-proliferative properties. The regenerated leaf and stem extract, however, could induce cell growth.

Plant photosynthesis is mainly dependent on leaf color, and this has an impact on yield. Mutants lacking in chlorophyll have been analyzed to gain insight into the genetic processes involved in photosynthesis, chloroplast development, and chlorophyll metabolism. A yellow-to-lethal mutant, ytl, was selected from the M₆ generation of the ⁶⁰Coγ ray irradiation-treated soybean cultivar Nannong 1138-2. The mutant exhibited reduced chlorophyll content, with the thylakoid structure disrupted. Segregation of the cross between Williams 82 (W82) and ytl indicated that a recessive allele controlled yellow-to-lethal traits. The bulked-segregant analysis (BSA)-Seq method performed preliminary mapping, followed by simple sequence repeat (SSR) marker validation and further mapping. The candidate gene was mapped to a 418 Kb region containing 53 genes. High-throughput sequencing and first-generation sequencing results showed a two bp deletion in the second exon of Glyma.08g106500, leading to a frameshift mutation in ytl. As a promising candidate gene, Glyma.08g106500 encoded a chloroplast-localized pentatricopeptide repeat (PPR) domain-containing protein involved in the assembly of chloroplast proteins. These results will contribute to cloning the mutant ytl gene and provide insight into the regulatory processes controlling photosynthesis and chloroplast development and growth in soybean.

The seeds of pumpkin (Cucurbita maxima Linn.) can be utilized as both a conventional and multifunctional dietary constituent. In this study the antioxidant, antibacterial, and cytotoxic effects of various fractions such as petroleum ether soluble fraction (PESF), chloroform soluble fraction (CFSF), dichloromethane soluble fraction (DCMSF), and aqueous soluble fraction (AQF) were obtained from crude extract (CE) of the C. maxima seeds were assessed by using 1,1-Diphenyl-2- Picrylhydrazyl (DPPH) method, disc diffusion technique, and brine shrimp lethality bioassay respectively. The results showed that all the fractions have remarkable antioxidant, antibacterial, and cytotoxic activities. The study revealed that both the AQF and PESF and the CF confirmed significant antioxidant properties. The antibacterial activity of different fractions against Gram-positive and Gram-negative bacteria was examined to determine their significant effect. PESF and CFSF fractions exhibited substantial inhibitory activity against Gram-positive bacteria, particularly Bacillus cereus. Bacillus subtilis exhibited significant susceptibility to both CFSF and AQF. Salmonella typhi and Shigella dysenteriae exhibited significant susceptibility to PESF and CFSF, while Escherichia coli was the Gram-negative bacterium most effectively inhibited by CFSF. The IC50 values revealed that the DCMSF exhibited the highest inhibitory activity, followed by other fractions. The new study emphasizes the significance of pumpkin seeds in terms of their pharmacological and biological properties, which may encourage more research on the potential benefits of this plant for human health. Jagannath University Journal of Life and Earth Sciences, 9(1): 7-18, 2023 (June)