Bananas and plantains, belonging to the Musa genus, are important food crops that sustain the livelihoods of countless smallholder farmers globally. However, their production is hindered by various challenges, including abiotic and biotic stresses, climate change, and poor access to clean planting materials, which negatively impact their yields. Addressing these constraints is essential for improving production and ensuring food security. This study investigated the influence of triploid genome background and exogenous growth regulators on the regeneration of Musa cultivars [Gros Michel (AAA genome), Obino l’Ewai and Silk (AAB genome), and Poteau Naine (ABB genome)]. Shoot tip explants of the AAA, AAB, and ABB triploid genomes were cultured in Murashige and Skoog (MS) media supplemented with varying 6-benzylaminopurine (BAP) and indole-3-butyric acid (IBA), indole-3-acetic acid (IAA), or naphthaleneacetic acid (NAA) hormones. Shoot induction was successfully achieved within 21.50 ± 2.00 days, with AAA exhibiting the highest shoot induction frequencies ranging from 30.00 ± 1.57% to 100% and shoot numbers per explant ranging from 3.00 ± 0.50 to 8.80 ± 0.80, followed by the ABB genome ranging from 20.00 ± 3.45% to 100% and from 2.00 ± 0.55 to 5.60 ± 0.50 shoots, and the AAB genome ranging from 17.50 ± 5.01% to 100% and from 2.00 ± 0.04 to 6.60 ± 0.25 shoots, respectively, in media amended with 1.2 to 6.0 mg.L⁻¹ BAP and 0.1 mg.L⁻¹ IAA. The highest rooting rate of 100% was recorded in all three genomes in media containing 1.4 mg.L⁻¹ IBA and 0.5 mg.L⁻¹ IAA, with the AAA genome producing the maximum number of 14.8 roots per explant. The results indicate the positive influence of the AAA genome background on in vitro regeneration and its potential utilization for genomic editing transformation protocols

Bitter melon (Momordica charantia L.), a widely cultivated food and medicinal plant native to the world's subtropics and tropics, is a Cucurbitaceae rich in carotenoids. However, the low seed germination frequency and progeny variability associated with the production of this plant have a substantial impact on its growth and yield. These constraints affect the availability and exploitation of this crop, especially the fruits, which are rich in secondary metabolites such as β-carotene and α-carotene. In vitro regeneration would help overcome the obstacle linked to the germination of this plant and increase its yield and utilization. A reproducible in vitro organogenesis protocol was established using bitter melon embryogenic callus derived from immature leaf explants of in vivo grown seedlings and in vitro plantlets. Regeneration via callus was conducted on MSB5 media augmented with different plant growth regulator concentrations. The maximum frequency of callus formation (95.09 %) was produced in MSB5 media incorporated with 1.2 mg L⁻¹ NAA augmented with 0.5 mg L⁻¹ TDZ. MSB5 medium with no growth regulators was observed to be the most suitable for the shoot and root formation from the callus, producing a significantly high shoot percentage of 90.91 % and 21.53 shoots per explants, and the highest rooting frequency and root number of 88.92 % and 6.23 roots per explant, respectively, from leaf-derived callus of in vitro plantlets. The elongated plantlets had grown to a significantly higher average height of 12.20 cm on media added with 0.75 mg L⁻¹ GA₃. This reproducible method for regenerating bitter melon plantlets could facilitate mass multiplication, conservation, and commercial field production.

The high quantity of polyphenols and polysaccharides present in the tissues of Musa spp. often leads to the degradation of nucleic acids, which is why all previously established methods resulted in lesser yield and poor quality of RNA. In this study, we present a modified SDS-based RNA extraction method to improve the quality and yield of RNA from different tissues of Musa spp. for downstream applications. The modification of RNA extraction buffer, SDS, heat incubation, and use of LiCl resulted in high-intensity RNA bands and increased RNA yield. The clear ribosomal RNA bands ensured the high quality of intact RNA without genomic DNA contamination, along with A260/A280 and A260/A230 ratios ranging from 1.83 to 2.25, which indicated the high quality of RNA across different banana varieties and tissue types. This method was found to be very effective when RNA was extracted from drought-stressed plants yielding 2.92 to 6.30 µg/100 mg fresh weight with high RNA integrity and quality (RNA IQ) 7.8–9.9 from the different groups of Musa tissues. Additionally, the RNA was successfully applied in PCR and quantitative real-time PCR (qRT-PCR), confirming downstream application in gene expression analysis. This method is a reliable and efficient technique for RNA extraction methods like Trizol, NucleoSpin, RNeasy, and CTAB procedures reported so far.

Doum palms (Hyphaene compressa) perform a crucial starring role in the lives of Kenya’s arid and semi-arid people for empowerment and sustenance. Despite the crop’s potential for economic gain, there is a lack of genetic resources and detailed information about its domestication at the molecular level. Given the doum palm’s vast potential as a widely distributed plant in semi-arid and arid climates and a source of many applications, coupled with the current changing climate scenario, it is essential to understand the molecular processes that provide drought resistance to this plant. Assembly of the first transcriptome of doum palms subjected to water stress generated about 39.97 Gb of RNA-Seq data. The assembled transcriptome revealed 193,167 unigenes with an average length of 1655 bp, with 128,708 (66.63%) successfully annotated in seven public databases. Unigenes exhibited significant differentially expressed genes (DEGs) in well-watered and stressed-treated plants, with 45071 and 42457 accounting for up-regulated and down-regulated DEGs, respectively. GO term, KEGG, and KOG analysis showed that DEGs were functionally enriched cellular processes, metabolic processes, cellular and catalytic activity, metabolism, genetic information processing, signal transduction mechanisms, and posttranslational modification pathways. Transcription factors (TF), such as the MYB, WRKY, NAC family, FAR1, B3, bHLH, and bZIP, were the prominent TF families identified as doum palm DEGs encoding drought stress tolerance. This study provides a complete understanding of DEGs involved in drought stress at the transcriptome level in doum palms. This research is, therefore, the foundation for the characterization of potential genes, leading to a clear understanding of its drought stress responses and providing resources for improved genetic modification.

Small non-coding microRNAs (miRNAs) play crucial roles in the degradation of the messenger RNAs (mRNAs) that are involved in various biological processes post-transcriptionally and translationally. Many plants, especially Musa spp. (plantains and bananas), which are important perennial herbs of the family Musaceae, experience significant yield loss due to abiotic stressors, yet only a few miRNAs involved in this response have been identified. This study employed in silico analyses of transcriptome shotgun assembly (TSA) and expressed sequence tag (EST) sequences to identify Musa miRNAs and their target genes. Leaf and root tissues from three Musa genomic groups (AAA, AAB, and ABB) under drought stress were analyzed using quantitative real-time PCR (qRT-PCR) to validate the expression of miRNAs. A total of 17 potential conserved miRNAs from 11 families were identified, with the minimal folding free energies (-kcal/mol) of precursors ranging from −136.00 to −55.70, as observed through RNA folding analysis. Six miRNAs (miR530-5p, miR528-5p, miR482a, miR397a, miR160h, and miR399a) showed distinct tissue-specific expression patterns in the roots and leaves across the three groups. A total of 59 target regulatory transcription factors and enzymes involved in stress response, growth, and metabolism were predicted. Of these, 11 targets were validated for miR530-5p, miR528-5p, miR482a, and miR397a, using qRT-PCR. These four stress-responsive miRNAs exhibited an inverse expression relationship with their target genes across two different tissues in Musa groups. This research provides insights into miRNA-mediated drought stress responsiveness in Musa spp., potentially benefiting future studies on gene regulation under drought stress.