Search

Oyster mushroom spherical virus (OMSV) is a mycovirus that inhibits mycelial growth, induces malformation symptoms, and decreases the yield of fruiting bodies in Pleurotus ostreatus. However, the pathogenic mechanism of OMSV infection in P. ostreatus is poorly understood. In this study, RNA sequencing (RNA-seq) was conducted, identifying 354 differentially expressed genes (DEGs) in the mycelium of P. ostreatus during OMSV infection. Verifying the RNA-seq data through quantitative real-time polymerase chain reaction on 15 DEGs confirmed the consistency of gene expression trends. Both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses highlighted the pivotal role of primary metabolic pathways in OMSV infection. Additionally, significant changes were noted in the gene expression levels of carbohydrate-active enzymes (CAZymes), which are crucial for providing the carbohydrates needed for fungal growth, development, and reproduction by degrading renewable lignocellulose. The activities of carboxymethyl cellulase, laccase, and amylase decreased, whereas chitinase activity increased, suggesting a potential mechanism by which OMSV influenced mycelial growth through modulating CAZyme activities. Therefore, this study provided insights into the pathogenic mechanisms triggered by OMSV in P. ostreatus. [ABSTRACT FROM AUTHOR]

In plants, ferritin proteins play an important role in iron (Fe) storage which contributes to plant growth and development. However, the biological functions of ferritins in fruit trees are essentially unknown. In this study, three Ferritin genes were isolated from 'Zhentong No. 3' peach, which were named PpFer1-PpFer3. The expression levels of these genes were different in distinct tissues/organs. Notably, PpFer1 was the most abundantly expressed Ferritin family gene in all tested tissues of 'Zhentong No. 3' peach; its expression levels were significantly enhanced throughout the entire peach seedling under Fe toxicity and H2O2 stress, particularly in the leaves. In addition, over-expression of PpFer1 was effective in rescuing the retarded growth of Arabidopsis fer1-2 knockout mutant, embodied in enhanced fresh weight, primary root length, lateral root numbers, total root length, total leaf chlorophyll, stomatal conductance (Gs), net photosynthetic rate (Pn), transpiration rate, and tissue Fe concentration. This study provides insights into understanding the molecular mechanisms of Fe storage and sequestration in perennial fruit trees. [ABSTRACT FROM AUTHOR]

Shaker-type K+ channels are critical for plant K+ acquisition and translocation that play key roles during plant growth and development. However, molecular mechanisms towards K+ channels are extremely rare in fruit trees, especially in peach. In this study, we identified 7 putative shaker-type K+ channel genes from peach, which were unevenly distributed on 5 chromosomes. The peach shaker K+ channel proteins were classified into 5 subfamilies, I-V, and were tightly clustered with pear homologs in the phylogenetic tree. Various cis-acting regulatory elements were detected in the promoter region of the shaker-type K+ channel genes, including phytohormone-responsive, abiotic stress-responsive, and development regulatory elements. The peach shaker K+ channel genes were expressed differentially in distinct tissues, and PpSPIK was specifically expressed in the full-bloom flowers; PpKAT1 and PpGORK were predominantly expressed in the leaves, while PpAKT1, PpKC1, and PpSKOR were majorly expressed in the roots. The peach shaker K+ channel genes were differentially regulated by abiotic stresses in that K+ deficiency, and ABA treatment mainly increased the shaker K+ channel gene expression throughout the whole seedling, whereas NaCl and PEG treatment reduced the shaker K+ channel gene expression, especially in the roots. Moreover, electrophysiological analysis demonstrated that PpSKOR is a typical voltage-dependent outwardly rectifying K+ channel in peach. This study lays a molecular basis for further functional studies of the shaker-type K+ channel genes in peach and provides a theoretical foundation for K+ nutrition and balance research in fruit trees. [ABSTRACT FROM AUTHOR]

As one of the most important micronutrients, iron (Fe) plays a critical role in various metabolic processes during plant growth and development. However, the molecular mechanisms towards Fe metabolism and nutrition in fruit trees are largely unknown. In this study, we examined the effects of amino acid-Fe compound fertilizer spraying on leaf development in peach (Prunus persica (L.) Batsch) at different developmental stages. Foliar spraying with amino acid-Fe compound fertilizer did not cause any significant changes in leaf morphology but remarkably increased leaf fresh weights. Fe concentration, photosynthetic parameter, and Fe-S protein analyses revealed that Fe accumulation, total chlorophyll content, net photosynthetic rate ( P N ), and stomatal conductance ( g s ), as well as nitrite reductase (NIR) and succinate dehydrogenase (SDH) activities, were significantly higher in the leaves sprayed with amino acid-Fe compound fertilizer than in the control leaves sprayed with distilled water. Further quantitative real-time PCR (qRT-PCR) analyses demonstrated that Fe-S cluster biosynthesis genes were differentially expressed in the leaves at different developmental stages. Foliar spraying with amino acid-Fe compound fertilizer significantly increased the expression of the most tested Fe-S cluster biosynthesis genes. Our findings provide new insights into the understanding of effects of Fe fertilization application on leaf development in perennial woody fruit trees. [ABSTRACT FROM AUTHOR]

Extracellular ATP (eATP) has long been established in animals as an important signalling molecule but this is less understood in plants. The identification of Arabidopsis thaliana DORN1 (Does Not Respond to Nucleotides) as the first plant eATP receptor has shown that it is fundamental to the elevation of cytosolic free Ca2+ ([Ca2+]cyt) as a possible second messenger. eATP causes other downstream responses such as increase in reactive oxygen species (ROS) and nitric oxide, plus changes in gene expression. The plasma membrane Ca2+ influx channels involved in eATP-induced [Ca2+]cyt increase remain unknown at the genetic level. Arabidopsis thaliana Annexin 1 has been found to mediate ROS-activated Ca2+ influx in root epidermis, consistent with its operating as a transport pathway. In this study, the loss of function Annexin 1 mutant was found to have impaired [Ca2+]cyt elevation in roots in response to eATP or eADP. Additionally, this annexin was implicated in modulating eATP-induced intracellular ROS accumulation in roots as well as expression of eATP-responsive genes. [ABSTRACT FROM AUTHOR]

The storage period of European pear (Pyrus communis L.) is prolonged at low temperature, but the pear softened quickly after shifting to room temperature. However, the molecular mechanisms that influence this process are unknown. In this study, 'Docteur Jules Guyot' pears were placed at room temperature (RT) and low temperature and then turned to room temperature (LR). The fruit firmness of 'Docteur Jules Guyot' under LR decreased faster than RT after moving from low temperature. The ethylene production rate, water-soluble pectin (WSP), ionic-soluble pectin (ISP) content, and pectin degradation enzyme activity of 'Docteur Jules Guyot' under LR increased faster than RT after moving from low temperature. RNA-seq of 'Docteur Jules Guyot' pear under different storage conditions was carried out, and 1018 genes were found to be negatively correlated with fruit firmness by the weighted gene coexpression network analysis (WGCNA) method. Then, 24 structural genes and transcription factors related to fruit softening were selected to verify the RNA-Seq results. The expression of all these selected genes increased significantly after LT storage. The fruit firmness, pectin content, and pectin degradation enzyme activity of 'Laiyang' pear did not change significantly under RT and LR storage conditions. The expression of LAX2 , ARF19 , EXP1 , EXPA1 , EXP3 and PG2 was upregulated in 'Docteur Jules Guyot' pear but downregulated in 'Laiyang' pear. These genes might play important roles in the softening process of European pear. This work laid the foundation for revealing the mechanisms of European pear fruit softening. • Low temperature accelerated the softening of 'Docteur Jules Guyot' pear after shifting to room temperature. • WGCNA identifies two key modules involved in pear fruit softening. • The expression trend of some genes in European and Asian pears was completely opposite. • LAX2 , ARF19 , EXP1 , EXPA1 , EXP3 and PG2 may play important roles in European pear softening. [ABSTRACT FROM AUTHOR]

• Transcriptome sequencing of the branches of 'Bartlett' and 'Red Bartlett'. • Weighted gene coexpression network analysis (WGCNA) identified 495 differentially expressed genes positively associated with anthocyanin. • The expression levels of one UFGT and one GST were also upregulated in the pericarps of 'Red Bartlett' and 'Starkrimson' than in 'Bartlett' and 'Clapps Favourite'. The color of the peel is the most direct reflection of fruit quality, and is also an important factor in attracting consumers. The 'Red Bartlett' pear (Pyrus communis L.) is a red bud sport mutant variety of 'Bartlett' pear. It was found that the anthocyanin content in branches and pericarps of 'Red Bartlett' pears were significantly higher than that of 'Bartlett' pears. The present study aimed to clarify the underlying mechanisms of anthocyanin accumulation in 'Red Bartlett' using a transcriptome analysis. A weighted gene coexpression network analysis (WGCNA) identified 495 differentially expressed genes positively associated with anthocyanin. Additionally, 12 anthocyanin-related structural genes and 13 transcription factors, including WRKY, ERF, bHLH, ASIL2, and HSF, were identified through screening of 495 DEGs. The expression levels of one UFGT (Pbr014258.1) and one GST (Pbr012649.1) were also upregulated in the pericarps of 'Red Bartlett' and 'Starkrimson', more so than in 'Bartlett' and 'Clapps Favourite'. Overall, this study clarified that the red color mutation of 'Red Bartlett' was closely linked to increased anthocyanin biosynthesis and transport. This study provided an abundance of valuable information on anthocyanin biosynthesis for future breeding of red-skinned pears. [ABSTRACT FROM AUTHOR]