Genomic Analysis of the Glutathione S-Transferase Family in Pear (Pyrus communis) and Functional Identification of PcGST57 in Anthocyanin Accumulation

Anthocyanin accumulation in vacuoles results in red coloration in pear peels. Glutathione S-transferase (GST) proteins have emerged as important regulators of anthocyanin accumulation. Here, a total of 57 PcGST genes were identified in the European pear ‘Bartlett’ (Pyrus communis) through comprehensive genomic analysis. Phylogenetic analysis showed that PcGST genes were divided into 10 subfamilies. The gene structure, chromosomal localization, collinearity relationship, cis-elements in the promoter region, and conserved motifs of PcGST genes were analyzed. Further research indicated that glutamic acid (Glu) can significantly improve anthocyanin accumulation in pear peels. RNA sequencing (RNA-seq) analysis showed that Glu induced the expression of most PcGST genes, among which PcGST57 was most significantly induced. Further phylogenetic analysis indicated that PcGST57 was closely related to GST genes identified in other species, which were involved in anthocyanin accumulation. Transcript analysis indicated that PcGST57 was expressed in various tissues, other than flesh, and associated with peel coloration at different developmental stages. Silencing of PcGST57 by virus-induced gene silencing (VIGS) inhibited the expression of PcGST57 and reduced the anthocyanin content in pear fruit. In contrast, overexpression of PcGST57 improved anthocyanin accumulation. Collectively, our results demonstrated that PcGST57 was involved in anthocyanin accumulation in pear and provided candidate genes for red pear breeding.

Insecticidal activity and phytochemical analysis of Pyrus communis L. extracts against malarial vector, Anopheles pharoensis Theobald, 1901 (Diptera: Culicidae)

We aimed at investigating the insecticidal activity of Pyrus communis L. against the malarial vector, Anopheles pharoensis Theobald, 1901 and its phytochemical constituents. Leaves were collected and the crude extracts were prepared using hexane (PCH) and methanol (PCM). Tested PCH and PCM possess larvicidal activity against A. pharoensis with LC50 and LC90 values of 179.9, 41.2 and 314.1, 68.9 ppm, respectively. A significant reduction in the number of eggs laid by females A. pharoensis that developed from larvae treated with PCH and PCM was noticed. Also, PCH treatment showed highest repellent activity compared with PCM. GC/MS analysis of the PCH revealed the presence of 55 identified compounds subdivided into 2 major classes viz. phenyl alkanes (38.65 %) and oxygenated sesquiterpenoids (36.41 %). LC/MS of PCM had led to the identification of 37 compounds, mainly flavonoids, chalcones, phenolic acids and tannins. The results demonstrate the insecticidal potential of leaves methanol and hexane extracts from P. communis as green insecticidal agents for the control of malarial vector, A. pharoensis.

Expansion of tree and shrub plant species into undisturbed steppe phytocenoses

The article is devoted to the study of tree and shrub plant species that spontaneously invasively colonize anthropogenically undisturbed steppe ecosystems. The species composition, number and biometric characteristics of tree and shrub plant species are determined. It was established that there are 22 species, among which 8 show the greatest invasive activity, in 6 studied natural beams. These are: Cotinus coggygria Scop., Crataegus fallacina L., Prunus divaricata Ledeb., Prunus stepposa Kotov, Pyrus communis L., Rhamnus cathartica L., Robinia pseudoacacia L., Ros corymbifera Borkh. According to the Serensen index of species composition of tree and shrub plants, comparing the slopes of beams of different exposures, it was found that steppe tracts have different similarities between the slopes, but the highest figure was observed for Balka Demurynа (80%).

Capa freática:

El objetivo fue analizar cuali-cuantitativamente el flujo capilar y evaluar su influencia en la programación del riego en un cultivo de pera (Pyrus communis) cv. William`s. Durante cuatro ciclos consecutivos se midieron con sensores específicos promedios diarios de humedad, potencial mátrico y salinidad del suelo y los niveles y salinidad de la freática. La profundidad de la freática fluctuó entre 1.00 m y 1.10 m y salinidad entre 1.5 y 1.6 dS.m-1. Los valores medios de la humedad del perfil de exploración radicular se encontraron en la franja del agua fácilmente disponible con un balance salino equilibrado. Con el programa WinIsareg se ajustó el balance hídrico simulado al contenido de humedad del suelo registrado por los sensores en cada uno de los ciclos. Las láminas de reposición resultantes se contrastaron con los requerimientos hídricos del cultivo y se estimaron los aportes del flujo capilar en 290 a 499 mm según la temporada. Estos representaron entre 1/3 y 2/3 del requerimiento hídrico del cultivo reduciendo la dotación media de riego entre un 35 a 64%. Los riegos realizados permitieron obtener rendimientos similares al valor de referencia en la zona y fueron 50% menos que los programados en condiciones de capa freática profunda.

Towards a catalog of pome tree architecture genes: the draft 'd'Anjou' genome (Pyrus communis L.)

The rapid development of sequencing technologies has led to a deeper understanding of horticultural plant genomes. However, experimental evidence connecting genes to important agronomic traits is still lacking in most non-model organisms. For instance, the genetic mechanisms underlying plant architecture are poorly understood in pome fruit trees, creating a major hurdle in developing new cultivars with desirable architecture, such as dwarfing rootstocks in European pear (Pyrus communis). Further, the quality and content of genomes vary widely. Therefore, it can be challenging to curate a list of genes with high-confidence gene models across reference genomes. This is often an important first step towards identifying key genetic factors for important traits. Here we present a draft genome of P. communis 'd'Anjou' and an improved assembly of the latest P. communis 'Bartlett' genome. To study gene families involved in tree architecture in European pear and other rosaceous species, we developed a workflow using a collection of bioinformatic tools towards curation of gene families of interest across genomes. This lays the groundwork for future functional studies in pear tree architecture. Importantly, our workflow can be easily adopted for other plant genomes and gene families of interest.