Strigolactones (SLs) were recently defined as a novel class of plant hormones that act as key regulators of diverse developmental processes and environmental responses. Much research has focused on SL biosynthesis and signaling in roots and shoots, but little is known about whether SLs are produced in early developing seeds and about their roles in ovule development after fertilization. This study revealed that the fertilized ovules and early developing pericarp in Xanthoceras sorbifolium produced minute amounts of two strigolactones: 5-deoxystrigol and strigol. Their content decreased in the plants with the addition of exogenous phosphate (Pi) compared to those without the Pi treatment. The exogenous application of an SL analog (GR24) and a specific inhibitor of SL biosynthesis (TIS108) affected early seed development and fruit set. In the Xanthoceras genome, we identified 69 potential homologs of genes involved in SL biological synthesis and signaling. Using RNA-seq to characterize the expression of these genes in the fertilized ovules, 37 genes were found to express differently in the fertilized ovules that were aborting compared to the normally developing ovules. A transcriptome analysis also revealed that in normally developing ovules after fertilization, 12 potential invertase genes were actively expressed. Hexoses (glucose and fructose) accumulated at high concentrations in normally developing ovules during syncytial endosperm development. In contrast, a low ratio of hexose and sucrose levels was detected in aborting ovules with a high strigolactone content. XsD14 virus-induced gene silencing (VIGS) increased the hexose content in fertilized ovules and induced the proliferation of endosperm free nuclei, thereby promoting early seed development and fruit set. We propose that the crosstalk between sugar and strigolactone signals may be an important part of a system that accurately regulates the abortion of ovules after fertilization. This study is useful for understanding the mechanisms underlying ovule abortion, which will serve as a guide for genetic or chemical approaches to promote seed yield in Xanthoceras.
The origin, classfication, germplasm resources and morphology is briefly reviewed in yardlong bean. The main agronomic characters such as pod color, seed coat color, petal color, grouth habit, maturity, stress resistance(Hardiness, Disease and Insect),heterosis, yield and quality and their inheritance are summarized. The application of the grey system theory to asparagus bean breeding is introduced. Some suggestions about the research of breeding in the future are discussed.
Goal: With the improvement of living standards, people's diets tend to be more and more high-fat, and long-term high-fat diets may lead to obesity and other chronic health problems. Nearly 80% of obese patients are accompanied by varying degrees of hepatic steatosis, so there is an urgent need to seek a safe and effective treatment of obesity and lipid deposition. Methods: In this study, 3-week-old Sprague-Dawley rats were divided into normal control group (NC), high-fat group: control group (HC), light fasting group (HI), exercise group (HE), light fasting plus exercise group (HIE), and light fasting, and aerobic exercise were used as intervention methods for 10 weeks. Catabolic protein effects were investigated to explore the effects of both on hepatic lipid deposition, and the experimental data were statistically analyzed using SPSS 25.0, with one-way or two-way ANOVA tests to be used, and graphs were made using GraphPad Prism 8.0. Findings: (1) Weight was significantly higher in the HC group compared to the NC group (p < 0.01). Compared with the HC group, the intervention group had lower body weight (P < 0.05), with the HIE group having a greater reduction in body weight. (2) The results of HE and oil red staining after 10 weeks of intervention showed that the liver structure and histological morphology of high-fat rats underwent significant improvement (P < 0.05), and the effect was more significant in the HIE group. (3) Compared with the NC group, serum TG, TC, LDL, AST, ALT were elevated (P < 0.05) and HDL was reduced (P < 0.05) in the HC group; compared with the HC group, TG, TC, LDL, AST, ALT were reduced, and HDL was elevated (P < 0.05) in the intervention group. (4) Compared with the NC group, the expression of p-AMPK/AMPK, p-ACC/ACC, and CPT1 was significantly reduced in the liver tissues of mice in the HC group (P < 0.01). The expression of p-AMPK/AMPK, p-ACC/ACC, and CPT1 was elevated in the liver tissues of the intervention group compared with the HC group (P < 0.05). Discussion: The present study confirmed that the effect of light fasting plus exercise on the improvement of lipid deposition was better than that of one alone, which provided a new idea and direction for the improvement of obesity and lipid deposition; however, this study did not go into depth on the mechanism at the molecular level, which needs to be continued to be explored.
Herbicide application is an efficient method to control weed growth in modern agriculture production, but there is concern about the ecological impact of unwanted herbicide residues in the soil. Rapeseed varieties ZS11 and D148 were used to evaluate the phytotoxic effects of residual glufosinate on the assimilation of nitrogen (N) in rapeseed seedlings transplanted to untreated [0 g hm−2 glufosinate] or treated [450 g hm−2 and 900 g hm−2 glufosinate] soils. Glutamine synthetase (GS) and glutamate dehydrogenase (GDH) activities, the contents of ammonium (NH4+), free amino acids (FAA), and soluble protein (SP), and seedling dry weight (DW) were determined at 5, 8, 11, 20, 40, and 70 d post-transplant. Both concentrations of glufosinate induced physiological phytotoxicity on the N assimilation of transplanted seedlings of both varieties, as their leaves and roots presented reduced GS activities and SP contents, and increased GDH activities, and NH4+ and FAA content. Glufosinate phytotoxicity on the N assimilation of transplanted seedlings reached a plateau at 11 to 20 d. further, GDH in roots and GS in leaves were still significantly different at 70 d. Meanwhile, ZS11 might be more sensitive to glufosinate than D148 since ZS11 had more variation than D148 at the same treatment, and the overdose of glufosinate more strongly inhibited N assimilation than the recommended dose. Therefore, it is essential to apply a suitable glufosinate dose to the transplanted variety, to minimize adverse effects on crops and the environment.Abbreviations: N, Nitrogen; GS, Glutamine synthetase; GDH, glutamate dehydrogenase; NH4+, ammonium; FAA, free amino acids; SP, soluble proteins; DW, Dry weight; ANOVA, one-way analysis of variance; NO3−, nitrate; OECD, Organisation for Economic Co-operation and Development; PPT, phosphinothricin; USEPA, United States Environmental Protection Agency
The development of Casparian strips (CSs) on the endo- and exodermis and their chemical components in roots of three cultivars of rice (Oryza sativa) with different salt tolerance were compared using histochemistry and Fourier transform infrared (FTIR) spectroscopy. The development and deposition of suberin lamellae of CSs on the endo- and exodermis in the salt-tolerant cultivar Liaohan 109 was earlier than in the moderately tolerant cultivar Tianfeng 202 and the sensitive cultivar Nipponbare. The detection of chemical components indicated major contributions to the structure of the outer part from aliphatic suberin, lignin, and cell wall proteins and carbohydrates to the rhizodermis, exodermis, sclerenchyma, and one layer of cortical cells in series (OPR) and the endodermal Casparian strip. Moreover, the amounts of these major chemical components in the outer part of the Liaohan 109 root were higher than in Tianfeng 202 and Nipponbare, but there was no distinct difference in endodermal CSs among the three rice cultivars. The results suggest that the exodermis of the salt-tolerant cultivar Liaohan 109 functions as a barrier for resisting salt stress.
Background Herbivore grazing is a multiple-component process that includes wounding, defoliation, and saliva deposition. Despite the extensive published research on mechanical wounding and defoliation, no analysis to identify the genes that specify defoliation and mechanical wounding has been performed. Moreover, the influence of the expression of these genes on plant regrowth after defoliation remains poorly understood. Results Seven cDNA libraries for RNA samples collected from stubble tissues that had been mechanically wounded or defoliated at 2, 6 and 24 h along with the control were sequenced using the Illumina/Solexa platform. A comparative transcriptomic analysis of the sequencing data was conducted. In total, 1,836 and 3,238 genes were detected with significant differential expression levels after wounding and defoliation, respectively, during one day. GO, KOG and pathway-based enrichment analyses were performed to determine and further understand the biological functions of those differentially expressed genes (DEGs). The results demonstrated that both wounding and defoliation activated the systemic synthesis of jasmonate (JA). However, defoliation specifically reduced the expression levels of ribosomal protein genes, cell division or cell expansion-related genes, and lignin biosynthesis genes and may have negatively affected plant growth. Further analysis revealed that the regrowth of elongating leaves was significantly retarded after defoliation at 6 h through the following 7 days of measurement, suggesting that the gene expression pattern and phenotype are consistent. Fifteen genes were selected, and their expression levels were confirmed by quantitative RT-PCR (qRT-PCR). Thirteen of them exhibited expression patterns consistent with the digital gene expression (DGE) data. Conclusions These sequencing datasets allowed us to elucidate the common and distinct mechanisms of plant responses to defoliation and wounding. Additionally, the distinct DEGs represent a valuable resource for novel gene discovery that may improve plant resistance to defoliation from various processes.
The ontogeny of floral organs and the morphology of floral apex in the dioecious Phellodendron amurense Rupr. were investigated by light microscopy (LM), scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM). Investigations indicated that P. amurense is hermaphroditic in its organisation and a common set of floral organs (sepals, petals, stamens and carpels) arise in all flowers during the early stages of development. Later, selective abortion of gynoecium and androecium occurs resulting in dimorphic unisexual flowers. The carpels in male flower buds become different from those in female flower buds soon after their initiation. The stamens of female flowers are not differentiated into anthers and filaments before abortion. The poorly differentiated carpel of male flowers never develops normal structures. Floral morphological evidence supports that Zanthoxylum, Tetradium and Phellodendron are related to one another in a linear sequence. LSCM revealed some interesting features on the apical meristem surface such as zonal differentiation, a triangular or sectorial cell, radiating cell files and linear rows of anticlinal cell walls fluorescing relatively brightly. The concept of carpel-enhancing meristem in the floral apex is tentatively proposed to account for the different fates of carpel development in male and female flowers in P. amurense.
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