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Plants or tissues can be regenerated through various pathways. Like animal regeneration, cell totipotency and pluripotency are the molecular basis of plant regeneration. Detailed systematic studies on Arabidopsis thaliana gradually unravel the fundamental mechanisms and principles underlying plant regeneration. Specifically, plant hormones, cell division, epigenetic remodeling, and transcription factors play crucial roles in reprogramming somatic cells and reestablishing meristematic cells. Recent research on basal non-vascular plants and monocot crops has revealed that plant regeneration differs among species, with various plant species using distinct mechanisms and displaying significant differences in regenerative capacity. Conducting multi-omics studies at the single-cell level, tracking plant regeneration processes in real-time, and deciphering the natural variation in regenerative capacity will ultimately help understand the essence of plant regeneration, improve crop regeneration efficiency, and contribute to future crop design. [ABSTRACT FROM AUTHOR]

Root-associated microbiomes contribute to plant growth and health, and are dynamically affected by plant development and changes in the soil environment. However, how different fertilizer regimes affect quantitative changes in microbial assembly to effect plant growth remains obscure. Here, we explore the temporal dynamics of the root-associated bacteria of soybean using quantitative microbiome profiling (QMP) to examine its response to unbalanced fertilizer treatments (i.e., lacking either N, P or K) and its role in sustaining plant growth after four decades of unbalanced fertilization. We show that the root-associated bacteria exhibit strong succession during plant development, and bacterial loads largely increase at later stages, particularly for Bacteroidetes. Unbalanced fertilization has a significant effect on the assembly of the soybean rhizosphere bacteria, and in the absence of N fertilizer the bacterial community diverges from that of fertilized plants, while lacking P fertilizer impedes the total load and turnover of rhizosphere bacteria. Importantly, a SynCom derived from the low-nitrogen-enriched cluster is capable of stimulating plant growth, corresponding with the stabilized soybean productivity in the absence of N fertilizer. These findings provide new insights in the quantitative dynamics of the root-associated microbiome and highlight a key ecological cluster with prospects for sustainable agricultural management. Root-associated microbiomes contribute to plant growth and health. Here, the authors unveil the quantitative development of the root microbiome under unbalanced fertilization and highlight a key microbial cluster for soybean productivity. [ABSTRACT FROM AUTHOR]

Chemokines are chemotactic-competent molecules composed of a family of small cytokines, playing a key role in regulating tumor progression. The roles of chemokines in antitumor immune responses are of great interest. CXCL9, CXCL10, and CXCL11 are important members of chemokines. It has been widely investigated that these three chemokines can bind to their common receptor CXCR3 and regulate the differentiation, migration, and tumor infiltration of immune cells, directly or indirectly affecting tumor growth and metastasis. Here, we summarize the mechanism of how the CXCL9/10/11–CXCR3 axis affects the tumor microenvironment, and list the latest researches to find out how this axis predicts the prognosis of different cancers. In addition, immunotherapy improves the survival of tumor patients, but some patients show drug resistance. Studies have found that the regulation of CXCL9/10/11–CXCR3 on the tumor microenvironment is involved in the process of changing immunotherapy resistance. Here we also describe new approaches to restoring sensitivity to immune checkpoint inhibitors through the CXCL9/10/11–CXCR3 axis. [ABSTRACT FROM AUTHOR]

Programmed cell death (PCD) plays an essential role in plant development and response to environmental stimuli. However, the underlying molecular regulatory mechanisms are largely unknown. In this study, we investigated the roles of the SMS1 gene to dissect its molecular mechanisms in rice PCD. The SMS1 gene was characterized by map-based cloning. Functional prediction and verification of the SMS1 gene were further conducted through complementation tests, subcellular localization assays, tissue-specific gene expression using GUS staining, and overexpression analysis using real-time quantitative RT-PCR. The sms1 mutant showed constitutive PCD, defective cell wall structure, and reduced pollen sterility. SMS1 encodes a uridine diphosphate glucose pyrophosphorylase (UGPase). SMS1 is ubiquitously expressed in rice, and the SMS1 protein localizes to both the cytoplasm and nucleus, implying a fundamental and crucial role in various rice tissues. Taken together, we demonstrate that by modulating UDP-glucose metabolism, SMS1 contributes to the maintenance of cell wall organization and cell viability in rice, providing, for the first time, evidence that sugar homeostasis regulates plant PCD. [ABSTRACT FROM AUTHOR]

Legumes, unlike other plants, have the ability to establish symbiosis with nitrogen-fixing rhizobia. It has been theorized that a unique property of legume root cortical cells enabled the initial establishment of rhizobial symbiosis1–3. Here we show that a SHORTROOT–SCARECROW (SHR–SCR) stem cell program in cortical cells of the legume Medicago truncatula specifies their distinct fate. Regulatory elements drive the cortical expression of SCR, and stele-expressed SHR protein accumulates in cortical cells of M. truncatula but not Arabidopsis thaliana. The cortical SHR–SCR network is conserved across legume species, responds to rhizobial signals, and initiates legume-specific cortical cell division for de novo nodule organogenesis and accommodation of rhizobia. Ectopic activation of SHR and SCR in legumes is sufficient to induce root cortical cell division. Our work suggests that acquisition of the cortical SHR–SCR module enabled cell division coupled to rhizobial infection in legumes. We propose that this event was central to the evolution of rhizobial endosymbiosis. Repurposing of an SHR–SCR stem cell program in the legume root cortex enables rhizobial symbiosis. [ABSTRACT FROM AUTHOR]

Main conclusion: The map-based cloning and application of a flower organ number gene twin - grain1 provide great potential for improving seed production in hybrid rice. Abstract: A new germplasm for high-yield rice breeding, the twin- grain1 ( tg1) mutant with more than one grain in a glume, was obtained from the Zhejing 22 rice variety via physical mutagenesis. The mapping results showed that TG1 is allelic to FLORAL ORGAN NUMBER2 (FON2)/FLORAL ORGAN NUMBER4 (FON4), a flower organ number gene located at 88.7 cM on chromosome 11. The novel tg1 gene allele was introgressed into the cytoplasmic male sterility (CMS) line Zhejing 22A, giving rise to a new CMS line Zhejing 22- tg1A. The Zhejing 22- tg1A line showed enhanced glume opening and stigma exsertion, which increased the outcrossing rate in hybrid rice. A small-scale hybrid rice seed production test demonstrated that the grain yield of the Zhejing 22- tg1A/Zhejinghui 5 line was significantly increased compared to that of the Zhejing 22A/Zhejinghui 5 line. The plot yield evaluation of the F hybrid lines showed a higher yield for the Zhejing 22- tg1A/Zhejinghui 5 line than that of the Zhejing 22A/Zhejinghui 5 line. The results implied great potentials for the tg1 gene in hybrid rice breeding. [ABSTRACT FROM AUTHOR]

The article discusses how DELLA protein complex controls the arbuscular mycorrhizal symbiosis in plants. Topics of discussion included were SLR1/DELLA, a repressor of gibberellic acid (GA) signaling, inhibition of mycorrhizal colonization by GA treatment in Pisum sativum, Oryzae sativa and mycorrhizal associated gene expression. Other topics were nutrient responses, light perception and signaling of several interacting hormones including auxin, ethylene and abscisic acid by DELLA.

The influence of L-arginine on endothelial nitric oxide synthase (eNOS) and cyclooxygenase 2 (COX2) was observed in experimental pulmonary thromboembolism and the action mechanism on pulmonary thromboembolism was explored. Wistar rats were randomly divided into control group, model group and treatment group. Pulmonary thromboembolism models were established by auto-blood back transfusion, and L-Arg 100 mg/kg was intraperitoneally injected after successful model preparation. The animals were sacrificed at 3 h, 1 day, 3 days and 7 days after embolism. Plasma NO, TXB2 and 6-Keto-PGF1α were detected. The expression of eNOS and COX2 protein and mRNA in pulmonary tissues was detected by immunohistochemistry and RT-PCR respectively. The results showed that pulmonary thrombosis could be seen post pulmonary embolism and inflammatory reaction was significant. Plasma NO was decreased ( P<0.01), and the levels of TXB2, 6-Keto-PGF1α and T/P ratio were all elevated. The expression of eNOS protein and mRNA in the pulmonary tissue was down-regulated ( P<0.05), while that of COX2 protein and mRNA was upregulated ( P<0.01). In treatment group, the level of NO was increased, the levels of TXB2 and T/P ratio were decreased, but the level of 6-Keto-PGF1α was increased. The expression of eNOS protein and mRNA in pulmonary tissue was upregulated ( P<0.05), while that of COX2 protein and mRNA was down-regulated ( P<0.05). In conclusion, L-arginine can educe the role of pulmonary tissue protection through up-regulating the expression of intra-pulmonary NOS and down-regulating COX2 in pulmonary thromboembolism. [ABSTRACT FROM AUTHOR]

Severe water deficit (SD) severely limited the photo-assimilate supply during the grain-filling stages. Although the ethylene and polyamines (PAs) have been identified as important signaling molecules involved in stress tolerance, it is yet unclear how 1-Aminocylopropane-1-carboxylic acid (ACC) and PA biosynthesis involving wheat abdominal phloem characters mitigate SD-induced filling inhibition. The results obtained indicated that the SD down-regulated the TaSUT1 expression and decreased the activities of sucrose synthase (SuSase, EC2.4.1.13), ADP glucose pyrophosphorylase (AGPase, EC2.7.7.27), soluble starch synthase (SSSase, EC2.4.1.21), then substantially limited grain filling. As a result, increased ACC and putrescine (Put) concentrations and their biosynthesis-related gene expression reduced spermidine (Spd) biosynthesis under SD condition. And, the ACC and PA biosynthesis in inferior grains was more sensitive to SD than that in superior grains. Intermediary cells (ICs) of caryopsis emerged prematurely under SD to compensate for the weakened photo-assimilate transport functions of sieve elements (SEs). Finally, plasmolysis and nuclear chromatin condensation of phloem parenchyma cells (PPC) and membrane degradation of SEs, as well as the decreased ATPase activity on plasma membranes of ICs and PPC at the later filling stage under SD were responsible for the considerably decreased weight of inferior grains. [ABSTRACT FROM AUTHOR]