The transcription factor family RELATED to ABSCISIC ACID INSENSITIVE3 (ABI3)/VIVIPAROUS1(VP1) (RAV) is a plant-specific group of transcription factors that only contain a conserved B3 DNA binding domain or both their own B3 and APETALA2 (AP2) domains belonging to the B3 superfamily, which is vital for plant growth, development, and stress response. Although genome-wide characterization and analysis of the RAV family genes have been conducted in some species, they have not been systematically reported in chrysanthemums. Here, we found six RAV family genes in the diploid Chrysanthemum seticuspe genome. Based on domain similarity and homology comparison analyses, RAV genes in Chrysanthemum were categorized into two clades: Class-I and Class-II. Conserved motif analysis revealed that all CsRAV proteins contained the B3 repression domain. An analysis of cis-acting elements suggested that CsRAV family genes may play parts in light, hormonal, abiotic stress, growth, and developmental processes. Furthermore, quantitative RT-PCR analysis validated that all six CsRAV genes responded to ethylene treatment, whereas the genes in the Class-I clade responded most significantly to ethylene. In summary, the above results provided a conceptual basis for further investigation into the functions of CsRAV genes in C. seticuspe. Full article

About ten species of the genus Actinidia Lindl. are known as cultivated plants—alongside the most known A. chinensis var. deliciosa, there are many others, including Far-Eastern cold-hardy kiwifruits such as A. arguta, A. kolomikta, and A. polygama. Unlike most plant species, in which the chloroplast genome is maternally inherited, the family Actinidiaceae possesses a complex system of plastid inheritance with possible transmission through both maternal and paternal lines. The main aim of this work was the assembly of the plastid genomes of three species of Actinidia, their comparison with already-available sequences from databases, and evolutionary analyses. We discovered that the gene composition and gene sequences are conserved; the studied species are either subject to purifying selection or not subject to selection at all (with some exceptions, such as the ycf2 gene). However, the chloroplast chromosomes of some Actinidia species have undergone significant structural rearrangements, leading to the persistence of two main forms, both on an intrageneric and intraspecific level. These results expand our understanding of plastid genomics and genetic diversity within the genus Actinidia, providing a basis for future research in molecular marker development, phylogenetic analysis, and population studies. Full article

Chrysanthemum mongolicum and Chrysanthemum vestitum belong to the Asteraceae family, which occupy a wider range of ecological niches and represent extensive biotic resistance and abiotic tolerance. However, the genetic information about these two species is poorly known, which restricts their utilization. Here, the leaf transcriptomes of the two Chrysanthemum species were investigated and compared. In total, 21,856 differentially expressed genes (DEGs) were identified between C. vestitum and C. mongolicum, of which 12,076 DEGs were up-regulated and 9780 were down regulated in C. vestitum compared to C. mongolicum. Functional enrichment analysis revealed that stress resistance categories had significant proportions. The up-regulated DEGs related to “ABC transporters”, “Flavonoid biosynthesis” and “Monoterpenoid biosynthesis” were significantly enriched in C. vestitum compared with C. mongolicum. While the DEGs involved in “Biosynthesis of unsaturated fatty acids”, “Proteasome”, “Phenylpropanoid biosynthesis”, “Oxidative phosphorylation”, “Plant-pathogen interaction”, “Starch and sucrose metabolism”, “Glutathione metabolism”, as well as “MAPK signaling pathway” were mostly up-regulated in C. mongolicum compared with C. vestitum, suggesting their important roles in C. mongolicum. These results might explain the differences in morphology and provide potential molecular mechanisms for the ecological adaptation of the two Chrysanthemum species in extreme environments. Together, the results of this study provide a genetic resource that may greatly benefit the genetic improvement of cultivated chrysanthemums and will be helpful for plant conservation and sustainable utilization in the future. Full article

The current study was designed to assess the comparative morphology of eight olive cultivars with different geographical origins and diverse genetic backgrounds, introduced to a new climatic zone. The morphological parameters of eight (five exotic and three domestic) olive cultivars (Bari Zaitoon-1, Bari Zaitoon-2, Favolosa (FS-17), Koroneiki, Balkasar, Ottobratica, Leccino, and Arbequina) were compared at the experimental area of the Department of Botany, The Islamia University of Bahawalpur, Pakistan (29°24′0″ North, 71°41′0″ East, 401–421 feet above sea level). Plant height, number of leaves/15 cm shoot, leaf size characteristics (leaf length, leaf width, leaf area, and length/width ratio), leaf shape characteristics (margin, leaf axil, base, and apex angles), leaf pigments (Chlorophyll a, Chlorophyll b, total chlorophyll contents, and carotenoids), phyllotaxy, and leaf color and venation were recorded. The highest plant height (28 cm) was obtained by Bari Zaitoon-2 followed by Bari Zaitoon-1 (24 cm), both of which are domestic cultivar of Pakistan, while the shortest height (5 cm) was obtained by Koroneiki. Leccino displayed the highest average number of leaves (17.8) on main shoot, followed by BARI-2 (16.4) and the lowest score was from Balkasar (10.4). Leaf area ranged from 5.66 cm² (Bari Zaitoon-1) to 3.08 cm² (Koroneiki). The longest leaf length (5.74 cm) was found in Bari Zaitoon-1 and the shortest (4.04 cm) in Koroneiki, while the broadest leaves were found in Leccino (1.54 cm) and the narrowest (1.12 cm) in Koroneiki. Bari Zaitoon-2 led in leaf length to width ratio (4.058) followed by Bari Zaitoon-1 (3.772) with small lanceolate leaves hardly reaching the value of 4, with the lowest value illustrated by Leccino. The total chloroplast pigments were highest in FS-17 followed by Bari Zaitoon-1 and Bari Zaitoon-2, while the lowest was in Arbequina. Chlorophyll a was highest in Bari Zaitoon-1 followed by FS-17 and Balkasar, with the lowest rate in Arbequina. Chlorophyll b content of FS-17 was the highest whereas the Chlorophyll b and total chlorophyll contents in Arbequina were the lowest of all the cultivars. The highest value of total carotenoids was found in Balkasar followed by FS-17 with the lowest value in Arbequina. The phyllotaxy was categorized into three types, i.e., alternate, opposite, and whorled. The combination of two or more types was usually observed on the same branch. The whorl of four leaves was also present in rare cases. Leaf venation was both pinnate and reticulate. The leaf base of most (four) of the olive cultivars, i.e., Arbequina, Balkasar, Leccino and FS-17, were cuneate having acute, rounded, apiculate, and cuspidate leaf tips, respectively. The findings revealed remarkable variations in olive morphology, especially in the leaves and a successful record of the preliminary data of olive cultivars from the study area was made. The present research demonstrated that local olive cultivars have unique characteristics that differentiate them from imported cultivars. Thus, local cultivars provide novel genetic resources that should be conserved. Full article

The GLK gene family is of great significance in regulating chloroplast development and participating in chlorophyll synthesis. However, the mechanism of GLK involvement in Citrus chlorophyll synthesis remains unclear. In this study, bioinformatics methods were used to analyze the gene structure, protein evolution, chromosome distribution, promoter elements and expression profile of GLK gene family in Citrus. Overall, 27 CsGLK TFs were identified from Citrus genome and divided into three subgroups according to the conserved domains. All members were distributed on nine chromosomes. The tandem replication events (ka/ks < 1) indicated that CsGLK TFs underwent a purification selection evolutionary process. The intron variation might be a vital configuration for the evolution of CsGLK genes. The expression pattern of CsGLKs showed that family members had higher expression levels in different tissues and at different growth stages and could actively respond to dark stress. CsGLK TFs of the same group had similar structures, but their expression patterns were quite different, indicating that they may have different functions and not be redundant. Correlation analysis showed that CsGLK2, CsGLK9, CsGLK10, CsGLK11, CsGLK20 and CsGLK24 were significantly positive correlations with Chl a and Chl b contents. In addition, CsGLK2, CsGLK5, CsGLK10, CsGLK11, CsGLK12, CsGLK15, CsGLK20 and CsGLK24 were significantly positive related to Mg-Proto IX, Proto IX and Pchl. Full article

In legumes, a LysM-RLK perception of rhizobial lipo-chitooligosaccharides (LCOs) known as Nod factors (NFs), triggers a signaling pathway related to the onset of symbiosis development. On the other hand, activation of LysM-RLKs upon recognition of chitin-derived short-chitooligosaccharides initiates defense responses. In this work, we identified the members of the LysM-RLK family in cultivated (Arachis hypogaea L.) and wild (A. duranensis and A. ipaensis) peanut genomes, and reconstructed the evolutionary history of the family. Phylogenetic analyses allowed the building of a framework to reinterpret the functional data reported on peanut LysM-RLKs. In addition, the potential involvement of two identified proteins in NF perception and immunity was assessed by gene expression analyses. Results indicated that peanut LysM-RLK is a highly diverse family. Digital expression analyses indicated that some A. hypogaea LysM-RLK receptors were upregulated during the early and late stages of symbiosis. In addition, expression profiles of selected LysM-RLKs proteins suggest participation in the receptor network mediating NF and/or chitosan perception. The analyses of LysM-RLK in the non-model legume peanut can contribute to gaining insight into the molecular basis of legume–microbe interactions and to the understanding of the evolutionary history of this gene family within the Fabaceae. Full article

The fungus Colletotrichum orbiculare causes watermelon anthracnose and is an important pathogen of watermelon in the United States, causing a significant impact on yield and quality of the produce. The application of fungicides as preventative and post-occurrence control measures is currently being deployed by growers. Further study of the genetic and molecular basis of anthracnose resistance will help in guiding future watermelon breeding strategies. Several conserved virulence factors (effectors) in C. orbiculare have been reported to interact with the host, at times impairing the host immune machinery. A single dominant gene conferring race 1 anthracnose resistance was reported independently on two watermelon germplasm. The recent advances in genomics, transcriptomics, proteomics, and metabolomics could facilitate a better understanding of the interaction between C. orbiculare effectors and host resistance genes in the already sequenced watermelon genome. In this review, we encompass and discuss (i) the history of watermelon anthracnose, taxonomy, morphology, and diversity in races of C. orbiculare; (ii) the epidemiology of the anthracnose disease and host resistance; (iii) the genetics behind the pathogenesis; and (iv) the current advances in breeding and molecular efforts to elucidate anthracnose resistance. Full article

The vast diversity of traits exhibited by horticultural crops largely depends upon variation in gene expression regulation. The uppermost layer of gene expression regulation is chromatin compaction. In plants, the LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) is a member of the Polycomb Repressive Complex 1 (PRC1) that controls the spreading of the H3K27me3 mark throughout the genome to regulate gene expression. Much of the epigenetic control exerted by LHP1 has been deeply explored on the model species Arabidopsis thaliana. Recent advances in melon, tomato, and soybean highlight the relevance of LHP1 in controlling the development and physiology of a plethora of traits in crops. However, whether LHP1 exerts its diverse roles through similar mechanisms and through modulating the same target genes has been overlooked. In this review, we gather a wealth of knowledge about the LHP1 mode of action, which involves a tight connection with histone marks and long noncoding RNAs to modulate gene expression. Strikingly, we found that LHP1 may be linked to H3K27me3 regulation across the plant lineage, yet, through epigenetic regulation of a distinct set of target genes. This is supported by subtle differences in subcellular LHP1 localization between species found here. In addition, we summarize the variety of developmental outputs modulated by LHP1 across land plants pinpointing its importance for plant breeding. Hence, LHP1 has probably been co-opted in different lineages to modulate diverse traits contributing to crop diversification. Full article