Recent advances in date palm genomics: A comprehensive review

A simple, rapid, cost-effective and reliable molecular technique for early sex determination in Phoenixdactylifera

The Phoenix dactylifera is an important horticultural cash crop in arid and semi-arid regions, known for its sweet, edible, nutritious fruit. Date palm is a diecious plant; females are commercially important to produce fruits, and males are required for pollination. Dates are easily segregated through seeds, then seed-raised plants revealed 50 % of each male and female plant. But a farmer needs a 95:5 ratio of female to male in the farming land. However, the gender of the plant can be identified four to five years after planting when it begins to flower, and there is no other method available for the identification of the gender. Hence, the present investigation focused on the development of techniques for the early sex determination of dates. Seventy-nine ISSR primers were used to analyze DNA from bulked female and male date palms. Among 79 markers, one marker, ISSR-49, has been selected and successfully validated in 105 female and 103 male date palm samples. The novel reliable biomarker (TG)8RC alone generates both female (400 bp) and male (600 bp) specific, unique amplicons. In conclusion, this investigation developed a simple, efficient, cost-effective technique that can discriminate the gender of date palms in a single PCR reaction within 5 h.

Enhancing Abiotic Stress Resilience in Mediterranean Woody Perennial Fruit Crops: Genetic, Epigenetic, and Microbial Molecular Perspectives in the Face of Climate Change

Enhanced abiotic stresses such as increased drought, elevated temperatures, salinity, and extreme weather phenomena severely affect major crops in the Mediterranean area, a 'hot spot' of climate change. Plants have evolved mechanisms to face stressful conditions and adapt to increased environmental pressures. Intricate molecular processes involving genetic and epigenetic factors and plant-microbe interactions have been implicated in the response and tolerance to abiotic stress. Deciphering the molecular mechanisms whereby plants perceive and respond to stress is crucial for developing strategies to counteract climate challenges. Progress in determining genes, complex gene networks, and biochemical pathways, as well as plant-microbiota crosstalk, involved in abiotic stress tolerance has been achieved through the application of molecular tools in diverse genetic resources. This knowledge could be particularly useful for accelerating plant improvement and generating resilient varieties, especially concerning woody perennial crops, where classical breeding is a lengthy and labor-intensive process. Similarly, understanding the mechanisms of plant-microbe interactions could provide insights into innovative approaches to facing stressful conditions. In this review, we provide a comprehensive overview and discuss the recent findings concerning the genetic, epigenetic, and microbial aspects shaping abiotic stress responses, in the context of enhancing resilience in important Mediterranean woody perennial fruit crops.

Boosting genome-wide association power and genomic prediction accuracy for date palm fruit traits with advanced statistics

The date palm is economically vital in the Middle East and North Africa, providing essential fibres, vitamins, and carbohydrates. Understanding the genetic architecture of its traits remains complex due to the tree's perennial nature and long generation times. This study aims to address these complexities by employing advanced genome-wide association (GWAS) and genomic prediction models using previously published data involving fruit acid content, sugar content, dimension, and colour traits. The multivariate GWAS model identified seven QTL, including five novel associations, that shed light on the genetic control of these traits. Furthermore, the research evaluates different genomic prediction models that considered genotype by environment and genotype by trait interactions. While colour- traits demonstrate strong predictive power, other traits display moderate accuracies across different models and scenarios aligned with the expectations when using small reference populations. When designing the cross-validation to predict new individuals, the accuracy of the best multi-trait model was significantly higher than all single-trait models for dimension traits, but not for the remaining traits, which showed similar performances. However, the cross-validation strategy that masked random phenotypic records (i.e., mimicking the unbalanced phenotypic records) showed significantly higher accuracy for all traits except acid contents. The findings underscore the importance of understanding genetic architecture for informed breeding strategies. The research emphasises the need for larger population sizes and multivariate models to enhance gene tagging power and predictive accuracy to advance date palm breeding programs. These findings support more targeted breeding in date palm, improving productivity and resilience to various environments.

DPXception: a lightweight CNN for image-based date palm species classification

Introduction

Date palm species classification is important for various agricultural and economic purposes, but it is challenging to perform based on images of date palms alone. Existing methods rely on fruit characteristics, which may not be always visible or present. In this study, we introduce a new dataset and a new model for image-based date palm species classification.

Methods

Our dataset consists of 2358 images of four common and valuable date palm species (Barhi, Sukkari, Ikhlas, and Saqi), which we collected ourselves. We also applied data augmentation techniques to increase the size and diversity of our dataset. Our model, called DPXception (Date Palm Xception), is a lightweight and efficient CNN architecture that we trained and fine-tuned on our dataset. Unlike the original Xception model, our DPXception model utilizes only the first 100 layers of the Xception model for feature extraction (Adapted Xception), making it more lightweight and efficient. We also applied normalization prior to adapted Xception and reduced the model dimensionality by adding an extra global average pooling layer after feature extraction by adapted Xception.

Results and discussion

We compared the performance of our model with seven well-known models: Xception, ResNet50, ResNet50V2, InceptionV3, DenseNet201, EfficientNetB4, and EfficientNetV2-S. Our model achieved the highest accuracy (92.9%) and F1-score (93%) among the models, as well as the lowest inference time (0.0513 seconds). We also developed an Android smartphone application that uses our model to classify date palm species from images captured by the smartphone's camera in real time. To the best of our knowledge, this is the first work to provide a public dataset of date palm images and to demonstrate a robust and practical image-based date palm species classification method. This work will open new research directions for more advanced date palm analysis tasks such as gender classification and age estimation.

A reference genome of Commelinales provides insights into the commelinids evolution and global spread of water hyacinth (Pontederia crassipes)

Commelinales belongs to the commelinids clade, which also comprises Poales that includes the most important monocot species, such as rice, wheat, and maize. No reference genome of Commelinales is currently available. Water hyacinth (Pontederia crassipes or Eichhornia crassipes), a member of Commelinales, is one of the devastating aquatic weeds, although it is also grown as an ornamental and medical plant. Here, we present a chromosome-scale reference genome of the tetraploid water hyacinth with a total length of 1.22 Gb (over 95% of the estimated size) across 8 pseudochromosome pairs. With the representative genomes, we reconstructed a phylogeny of the commelinids, which supported Zingiberales and Commelinales being sister lineages of Arecales and shed lights on the controversial relationship of the orders. We also reconstructed ancestral karyotypes of the commelinids clade and confirmed the ancient commelinids genome having 8 chromosomes but not 5 as previously reported. Gene family analysis revealed contraction of disease-resistance genes during polyploidization of water hyacinth, likely a result of fitness requirement for its role as a weed. Genetic diversity analysis using 9 water hyacinth lines from 3 continents (South America, Asia, and Europe) revealed very closely related nuclear genomes and almost identical chloroplast genomes of the materials, as well as provided clues about the global dispersal of water hyacinth. The genomic resources of P. crassipes reported here contribute a crucial missing link of the commelinids species and offer novel insights into their phylogeny.

Crosstalk between alternative splicing and inflammatory bowel disease: Basic mechanisms, biotechnological progresses and future perspectives

BACKGROUND

Alternative splicing (AS) is an omnipresent regulatory mechanism of gene expression that enables the generation of diverse splice isoforms from a single gene. Recently, AS events have gained considerable momentum in the pathogenesis of inflammatory bowel disease (IBD).

METHODS

Our review has summarized the complex process of RNA splicing, and firstly highlighted the potential involved molecules that target aberrant splicing events in IBD. The quantitative transcriptome analyses such as microarrays, next-generation sequencing (NGS) for AS events in IBD have been also discussed.

RESULTS

Available evidence suggests that some abnormal splicing RNAs can lead to multiple intestinal disorders during the onset of IBD as well as the progression to colitis-associated cancer (CAC), including gut microbiota perturbations, intestinal barrier dysfunctions, innate/adaptive immune dysregulations, pro-fibrosis activation and some other risk factors. Moreover, current data show that the advanced technologies, including microarrays and NGS, have been pioneeringly employed to screen the AS candidates and elucidate the potential regulatory mechanisms of IBD. Besides, other biotechnological progresses such as the applications of third-generation sequencing (TGS), single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST), will be desired with great expectations.

CONCLUSIONS

To our knowledge, the current review is the first one to evaluate the potential regulatory mechanisms of AS events in IBD. The expanding list of aberrantly spliced genes in IBD along with the developed technologies provide us new clues to how IBD develops, and how these important AS events can be explored for future treatment.