Arabidopsis seedlings respond differentially to nutrient efficacy of three rock meals by regulating root architecture and endogenous auxin homeostasis.

BACKGROUND: Plants show developmental plasticity with variations in environmental nutrients. Considering low-cost rock dust has been identified as a potential alternative to artificial fertilizers for more sustainable agriculture, the growth responses of Arabidopsis seedlings on three rock meals (basalt, granite, and marlstone) were examined for the different foraging behavior, biomass accumulation, and root architecture. RESULTS: Compared to ½ MS medium, basalt and granite meal increased primary root length by 13% and 38%, respectively, but marlstone caused a 66% decrease, and they all drastically reduced initiation and elongation of lateral roots but lengthened root hairs. Simultaneous supply of organic nutrients and trace elements increased fresh weight due to the increased length of primary roots and root hairs. When nitrogen (N), phosphorus (P), and potassium (K) were supplied individually, N proved most effective in improving fresh weight of seedlings growing on basalt and granite, whereas K, followed by P, was most effective for those growing on marlstone. Unexpectedly, the addition of N to marlstone negatively affected seedling growth, which was associated with repressed auxin biosynthesis in roots. CONCLUSIONS: Our data indicate that plants can recognize and adapt to complex mineral deficiency by adjusting hormonal homeostasis to achieve environmental sensitivity and developmental plasticity, which provide a basis for ecologically sound and sustainable strategies to maximize the use of natural resources and reduce the production of artificial fertilizers.

Advancements in the research of finger-actuated POCT chips.

Microfluidic point-of-care testing (POCT) chips are used to enable the mixing and reaction of small sample volumes, facilitating target molecule detection. Traditional methods for actuating POCT chips rely on external pumps or power supplies, which are complex and non-portable. The development of finger-actuated chips has reduced operational difficulty and improved portability, promoting the development of POCT chips. This paper reviews the significance, developments, and potential applications of finger-actuated POCT chips. Three methods for controlling the flow accuracy of finger-actuated chips are summarized: direct push, indirect control, and sample injection control method, along with their respective advantages and disadvantages. Meanwhile, a comprehensive analysis of multi-fluid driving modes is provided, categorizing them into single-push multi-driving and multi-push multi-driving modes. Furthermore, recent research breakthroughs in finger-actuated chips are thoroughly summarized, and their structures, driving, and detection methods are discussed. Finally, this paper discusses the driving performance of finger-actuated chips, the suitability of detection scenarios, and the compatibility with existing detection technologies. It also provides prospects for the future development and application of finger-actuated POCT chips.

Comparison of the efficacy and safety of antibiotic treatment and appendectomy for acute uncomplicated appendicitis: a systematic review and meta-analysis.

OBJECTIVE: This meta-analysis aimed to compare the efficacy and safety of antibiotic treatment and appendectomy for acute uncomplicated appendicitis. METHODS: We searched the randomized controlled studies (RCTs) comparing appendectomy with antibiotic treatment for uncomplicated acute appendicitis in the electronic database including Pubmed, Embase, Cochrane, Web of Science, CNKI, VIP, and WanFang. The primary outcomes included complication-free treatment success at 1 year, complications, surgical complications, and the complicated appendicitis rates. Secondary outcomes included negative appendicitis, length of hospital stay, the quality of life at 1 month, and the impact of an appendicolith on antibiotic therapy. RESULTS: Twelve randomized controlled studies were included. Compared with surgery group, the antibiotic group decreased the complication-free treatment success at 1 year (RR 0.81; 95% CI 0.73-0.91; z = 3.65; p = 0.000). Statistically significance was existed between antibiotic group and surgical group with both surgical types(open and laparoscopic) (RR 0.43; 95% CI 0.31-0.58; z = 5.36; p = 0.000), while no between the antibiotic treatment and laparoscopic surgery (RR 0.72; 95% CI 0.41-1.24; z = 1.19; p = 0.236). There was no statistically significant differences between two groups of surgical complications (RR 1.38; 95% CI 0.70-2.73; z = 0.93; p = 0.353), the complicated appendicitis rate (RR 0.71; 95% CI 0.36-1.42; z = 0.96; p = 0.338), negative appendectomy rate (RR 1.11; 95% CI 0.69-1.79; z = 0.43; p = 0.670), duration of hospital stay (SMD 0.08; 95%CI -0.11-0.27; z = 0.80; p = 0.422), and quality of life at 1 month (SMD 0.09; 95%CI -0.03-0.20; z = 1.53; p = 0.127). However, in the antibiotic treatment group, appendicolith rates were statistically higher in those whose symptoms did not improve (RR 2.94; 95% CI 1.28-6.74; z = 2.55; p = 0.011). CONCLUSIONS: Although the cure rate of antibiotics is lower than surgery, antibiotic treatment is still a reasonable option for patients with uncomplicated acute appendicitis who do not want surgery without having to worry about complications or complicating the original illness.

Improved efficiency of Sedum lineare (Crassulaceae) in remediation of arsenic-contaminated soil by phosphate-dissolving strain P-1 in association with phosphate rock.

The selection of appropriate plants and growth strategies is a key factor in improving the efficiency and universal applicability of phytoremediation. Sedum lineare grows rapidly and tolerates multiple adversities. The effects of inoculation of Acinetobacter sp. phosphate solubilizing bacteria P-1 and application of phosphate rock (PR) as additives on the remediation efficiency of As-contaminated soil by S. lineare were investigated. Compared with the control, both the single treatment and the combination of inoculation with strain P-1 and application of PR improved the biomass by 30.7-395.5%, chlorophyll content by 48.1-134.8%, total protein content by 12.5-92.4% and total As accumulation by 45.1-177.5%, and reduced the As-induced oxidative damage. Inoculation with strain P-1 increased the activities of superoxide dismutases and catalases of S. lineare under As stress, decreased the accumulation of reactive oxygen species in plant tissues and promoted the accumulation of As in roots. In contrast, simultaneous application of PR decreased As concentration in S. lineare tissues, attenuated As-induced lipid peroxidation and improved As transport to shoots. In addition, the combined application showed the best performance in improving resistance and biomass, which significantly increased root length by 149.1%, shoot length by 33%, fresh weight by 395.5% and total arsenic accumulation by 159.2%, but decreased the malondialdehyde content by 89.1%. Our results indicate that the combined application of strain P-1 and PR with S. lineare is a promising bioremediation strategy to accelerate phytoremediation of As-contaminated soils.

Overexpression of SHORT-ROOT2 transcription factor enhances the outgrowth of mature axillary buds in poplar trees.

SHORT-ROOT (SHR) transcription factors play important roles in asymmetric cell division and radial patterning of Arabidopsis roots. In hybrid poplar (P. tremula × P. alba clone INRA 717-1B4), PtaSHR2 was preferentially expressed in axillary buds (AXBs) and transcriptionally up-regulated during AXB maturation and activation. Overexpression of SHR2 (PtSHR2OE) induced an enhanced outgrowth of AXBs below the bud maturation point, with a simultaneous transition of an active shoot apex into an arrested terminal bud. The larger and more mature AXBs of PtSHR2OE trees revealed altered expression of genes involved in axillary meristem initiation and bud activation, as well as a higher ratio of cytokinin to auxin. To elucidate the underlying mechanism of PtSHR2OE-induced high branching, subsequent molecular and biochemical studies showed that compared with wild-type trees, decapitation induced a quicker bud outburst in PtSHR2OE trees, which could be fully inhibited by exogenous application of auxin or cytokinin biosynthesis inhibitor, but not by N-1-naphthylphthalamic acid. Our results indicated that overexpression of PtSHR2B disturbed the internal hormonal balance in AXBs by interfering with the basipetal transport of auxin, rather than causing auxin biosynthesis deficiency or auxin insensitivity, thereby releasing mature AXBs from apical dominance and promoting their outgrowth.

The prognostic effect of PNN in digestive tract cancers and its correlation with the tumor immune landscape in colon adenocarcinoma.

BACKGROUND: The present study investigated the expression, mutation, and methylation profile of PNN and its prognostic value in digestive tract cancers. The disparities in signaling pathways and the immune landscape in colon adenocarcinoma (COAD) based on PNN expression were specifically explored. METHODS: The expression, mutation, methylation levels of PNN, and survival data in esophageal cancer, gastric adenocarcinoma, COAD, and rectal adenocarcinoma were evaluated using several bioinformatic databases. Gene Ontology (GO) enrichment analysis and gene set enrichment analysis (GSEA) were performed to investigate the enriched biological functions and pathways in COAD. Several acknowledged bioinformatic algorithms were employed to assess the correlation between PNN expression and the tumor immune landscape in COAD. RESULTS: PNN was upregulated and remarkably related to tumor stage in digestive tract cancers. High expression of PNN was positively associated with poor progression-free survival and overall survival time, specifically in COAD. PNN expression was identified as an independent prognostic factor in COAD. GO and GSEA analyses revealed that PNN participates in multiple biological processes underlying carcinogenicity in COAD. Further investigation showed that PNN expression was significantly associated with tumor-infiltrating immune cells, immune cell functions, and several immune checkpoints in COAD. The PNN low expression group had a lower tumor immune dysfunction and exclusion (TIDE) score and a higher immunophenoscore (IPS), indicating a better response to immunotherapy. CONCLUSION: PNN was highly expressed in digestive tract cancers and could act as an independent prognostic factor and a response predictor for immunotherapy in COAD.

Upregulation of INHBA mediated by the transcription factor BHLHE40 promotes colon cancer cell proliferation and migration.

BACKGROUND: Colon cancer is highly prevalent, and cell proliferation and migration are major reasons for its progression to malignancy. The upregulation of INHBA, a glycoprotein hormone that regulates the secretion of pituitary hormones, is documented to be oncogenic in numerous cancers, consisting of breast, gastric, and ovarian cancer. Herein, we assessed the role of INHBA in the proliferation along with the migration of colon cancer cells. METHODS: TCGA datasets were used to assess INHBA expression and its correlation with prognosis in colon cancer patients. Analyses on JASPAR, PROMO, and ENCODE databases, uncovered high correlation between INHBA and BHLHE40. Western blot and RT-qPCR analysis were used to determine protein and mRNA levels. Cell transfection inhibited the expression of INHBA and BHLHE40. Cell proliferation rates were determined using CCK8 analysis. Wound healing assays were adopted to explore cell migration. RESULTS: INHBA is markedly elevated in colon cancer tissues along with cells and is a predictive factor for patient's prognosis with colon cancer. INHBA silencing suppressed colon cancer cell proliferation and migration. Furthermore, we confirmed the association of INHBA with BHLHE40 in colon cancer cells. BHLHE40 could directly modulates INHBA expression. Here, we show that BHLHE40 modulates the expression of INHBA, which influences the proliferation, and migration of colon cancer cells. CONCLUSION: INHBA acts as an oncogene in colon cancer and it can be regulated by the transcription factor BHLHE40.

Left colic artery diameter is an important factor affecting anastomotic blood supply in sigmoid colon cancer or rectal cancer surgery: a pilot study.

BACKGROUND: Anastomotic blood supply is vital to anastomotic healing. The aim of this study was to demonstrate the effect of the left colic artery (LCA) on blood supply in the anastomotic area, explore the relationship between individual differences in the LCA and blood supply in the anastomotic area, and elucidate the relevant indications for LCA retention during radical resection for sigmoid or rectal cancer. METHOD: Radical sigmoid or rectal cancer resection with LCA retention was performed in 40 patients with colorectal cancer who participated in this study. Systemic pressure, LCA diameter, and the distance from the root of the LCA to the root of the inferior mesenteric artery were measured and recorded. The marginal artery stump pressure in the anastomotic colon before and after the LCA clamping was measured, respectively. RESULTS: There is a significant difference between the marginal artery stump pressure before LCA ligation and after ligation (53.1 ± 12.38 vs 42.76 ± 12.71, p < 0.001). The anastomotic blood supply positively and linearly correlated with body mass index and systemic pressure. Receiver-operating curve analysis revealed that LCA diameter (area under the curve 0.971, cutoff 1.95 mm) was an effective predictor of LCA improving anastomosis blood supply. No relationship was found between the LCA root location and anastomotic blood supply. CONCLUSION: Preserving the LCA is effective in improving blood supply in the anastomotic area, and larger LCA diameters result in a better blood supply to the anastomotic area.

Apatinib weakens resistance of gastric cancer cells to paclitaxel by suppressing JAK/STAT3 signaling pathway.

Apatinib has experienced a long-term study in enhancing the sensitivity of various cancer cells to chemotherapy drugs. Currently, researches show that apatinib could attenuate the resistance of gastric cancer (GC) cells to paclitaxel (PTX), but the mechanism has not been fully elucidated, which therefore was explored in this study. PTX-resistant GC cell, namely HGC-27R, was established by exposure to stepwise-increasing PTX. The cell viability of HGC-27 and HGC-27R under PTX or apatinib at different concentrations was assessed by CCK-8 assay, while scratching test and invasion assay were used for investigating the harmful influence of GC cells resistance to PTX. The function of apatinib in HGC-27R was studied by performing functional experiments (flow cytometry, scratching test, and invasion assay). Western blot was performed to measure the expressions of proteins concerning apoptosis, epithelial-mesenchymal transition and janus-activated kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. PTX-resistant GC cell, namely HGC-27R, was successively constructed. HGC-27R cells showed resistance to PTX by promoting migratory and invasive capabilities. Apatinib not only inhibited cell viability of HGC-27 and HGC-27R, but also combined with PTX to suppress that of HGC-27R. Apatinib enhanced apoptosis, diminished migration and invasion of HGC-27R cells, elevated proapoptotic protein expression, and reduced Bcl-2, vimentin, snail, MMP-3, MMP-2, and MMP-9 expressions. The phosphorylation of JAK2 and STAT3 was repressed by apatinib. JAK2 partially reversed the effect of apatinib on enhancing sensitivity of GC cells to PTX. Apatinib strengthened sensitivity of GC cells to PTX by inhibiting JAK/STAT3 signaling pathway.

Copper-Catalyzed Difluoroalkylation Reaction.

This review describes recent advances in copper-catalyzed difluoroalkylation reactions. The RCF2 radical is generally proposed in the mechanism of these reactions. At present, various types of copper-catalyzed difluoroalkylation reactions have been realized. According to their characteristics, we classify these difluoroalkylation reactions into three types.

Puerarin protects cardiomyocytes from ischemia-reperfusion injury by upregulating LncRNA ANRIL and inhibiting autophagy.

This study analyzed the roles of puerarin and LncRNA ANRIL in myocardial ischemia-reperfusion injury. Hypoxia/reperfusion (H/R) model was established with H9C2 cells. Effects of puerarin of gradient concentrations on cardiomyocytes at different time points of hypoxia and reoxygenation were detected by quantitative real-time polymerase chain reaction (qRT-PCR), cell counting kit-8 (CCK-8), and microscope observation. Effects of puerarin on cardiomyocyte viability, ANRIL expression, contents of lactate dehydrogenase (LDH) and malondialdehyde (MDA), apoptosis, and expressions of autophagy-related genes after H/R injury were determined by CCK-8, quantitative real-time polymerase chain reaction (qRT-PCR), ELISA, flow cytometry, and Western blot, respectively. After cell transfection, the effects of overexpressed and knockdown of ANRIL on cardiomyocytes and H/R-injured cardiomyocytes were examined by rescue experiments. The ischemia-reperfusion (I/R)-injured rat model was established to examine the protective effect of puerarin in vivo. Prolonged hypoxia downregulated ANRIL expression in cardiomyocytes and reduced cardiomyocyte viability. Prolonged reoxygenation increased apoptosis. Both cardiomyocyte viability and ANRIL expression showed a dose-dependent relationship with puerarin. Puerarin reversed the effects of H/R injury on cardiomyocyte viability, ANRIL expression, contents of LDH and MDA, apoptosis, and expressions of autophagy-related genes. Overexpression and knockdown of ANRIL regulated the functions of cardiomyocytes and the expressions of autophagy-related genes. Puerarin reversed the effects of knockdown of ANRIL on H/R-injured cells. The results of In vivo experiments confirmed that puerarin protected myocardial tissues by up-regulating ANRIL and inhibiting autophagy.

TDIF peptides regulate root growth by affecting auxin homeostasis and PINs expression in Arabidopsis thaliana.

MAIN CONCLUSION: TDIF and TDIF-like peptides in excess simultaneously facilitate primary root elongation and lateral root formation through regulating auxin distribution and transport. Tracheary element differentiation inhibitory factor (TDIF) plays key roles in mediating cell-cell communication and stem cell maintenance during vascular development. Recently, TDIF has also been linked to lateral root (LR) organogenesis through Brassinosteroid Insensitive 2 (BIN2) action. In this work, by comparing the in vitro and in vivo activities of AtCLE41-encoded TDIF and one poplar-derived TDIF-like peptide in Arabidopsis thaliana, we demonstrated that both TDIFs promoted primary root (PR) growth and stimulated LR formation. Without affecting auxin biosynthesis and catabolism, TDIFs suppressed the auxin maxima at PR apex but intensified the auxin accumulation at LR initiation sites along the longitudinal axis of PR. TDIF did not alter root sensitivity to exogenous auxin and mutants with varied endogenous auxin levels responded to TDIF peptides in a wild-type manner but to a lesser extent. Intriguingly, TDIF specifically upregulated the transcript abundance of PINs and multiple pin mutants displayed insensitivity to TDIF, demonstrating that PIN-mediated polar auxin transport (PAT) is indispensably required for the TDIF-induced root phenotypes. Taken together, our results revealed that TDIF might target PAT via mobilizing auxin efflux carriers to dynamically regulate the auxin signaling output and hence facilitate PR growth and LR formation.

Protective effect of tanshinone IIA on H2O2-induced oxidative stress injury in rat cardiomyocytes by activating Nrf2 pathway.

To investigate the protective effect of tanshinone IIA on H2O2-induced oxidative stress injury in rat cardiomyocytes, and further to study its potential mechanisms. H9C2 cells were used to establish H2O2 injury model. The cell viability and apoptosis were detected by CCK-8 assay and flow cytometry, respectively. ELISA was used to detect the levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Moreover, the levels of malondialdehyde (MDA) and catalase (CAT) were tested by TBA and visible light methods, respectively. The Nrf2 pathway-related proteins were detected by Western blot. To validate the protective effect of tanshinone IIA on rat cardiomyocytes is worked by regulating the Nrf2 pathway, we further silenced Nrf2 and the above experiments were repeated. Tanshinone IIA could promote the proliferation, and reduce the apoptosis and ROS of rat cardiomyocytes induced by H2O2. Tanshinone IIA also could increase the activity of SOD, CAT, and GSH-Px, and decreased the activity of MDA and LDH. The protein expression of Nrf2, HO-1, and NQO1 was significantly up-regulated in tanshinone IIA groups, while the protein expression of Keap1 was significantly down-regulated. A further study has shown that silenced Nrf2 has completely opposite results. All those results suggested that tanshinone IIA could protect H2O2-induced oxidative stress injury in rat cardiomyocytes by activating Nrf2 pathway.

Overexpression of a Eutrema salsugineum phosphate transporter gene EsPHT1;4 enhances tolerance to low phosphorus stress in soybean.

OBJECTIVE: To enhance Pi absorption and utilization efficiency of soybean, a member of PHT1 gene family was isolated and characterized from E. salsugineum, which was a homologous gene of AtPHT1;4 and consequently designated as EsPHT1;4. RESULTS: Quantitative real-time PCR (qRT-PCR) analysis showed that the transcript level of EsPHT1;4 significantly increased both in roots and leaves of E. salsugineum under Pi deficient conditions. Furthermore, EsPHT1;4 was transferred to soybean cultivar "YD22" using an Agrobacterium-mediated cotyledonary-node transformation method. Overexpression of EsPHT1;4 in soybean not only promoted the increase of plant biomass and yield of transgenic plants upon low P stress, but also increased the accumulation and transportation of Pi from roots to leaves in the transgenic soybean lines. CONCLUSION: EsPHT1;4 was critical for controlling the accumulation and translocation of Pi in plants, and can be subsequently used as an effective foreign gene for the improvement of P use efficiency of crops by genetic manipulation.

Transcriptome sequencing and functional analysis of Sedum lineare Thunb. upon salt stress.

Soil salinization is one major constraint to plant geographical distribution, yield, and quality, and as an ideal plant for the "greening" of flat-roofed buildings, Sedum lineare Thunb. has strong tolerance against a variety of environmental adversities including salinity with the underlying mechanism still remaining unknown. In this study, we performed de novo transcriptome sequencing on leaf and root samples of NaCl-treated S. lineare Thunb. and identified 584 differentially expressed genes (DEGs), which were further annotated by gene function classification and pathway assignments using the public data repositories. In addition to the increased gene expression level verified by qRT-PCR, the elevated activities of the corresponding enzymes were also demonstrated for peroxidase (POD), glutathione peroxidases (GPX), and cysteine synthase (CSase) in the NaCl-treated roots. Furthermore, two highly inducible genes without known functions related to salt tolerance were selected to be overexpressed and tested for their effects on salt tolerance in the model plant, Arabidopsis thaliana. Upon 150 mM NaCl treatment, 35S:SlCXE but not 35S:SlCYP72A transgenic Arabidopsis seedlings exhibited improved salt resistance as shown by the increased seed germination rates and longer primary roots of transgenic seedlings when compared to wild-type plants. Taken together, this work laid a foundation for a better understanding of the salt adaptation mechanism of S. lineare Thunb. and genes identified could serve as useful resources for the development of more salt-tolerant varieties of other species through genetic engineering.

Distinct transgenic effects of poplar TDIF genes on vascular development in Arabidopsis.

KEY MESSAGE: Poplar CLE genes encoding TDIF motifs differentially regulate vascular cambial cell division and woody tissue organization in transgenic Arabidopsis. In Arabidopsis, CLE41 and CLE44 genes encode the tracheary element differentiation inhibitory factor (TDIF) peptide, which functions as a non-cell autonomous signal to regulate vascular development, and overexpression of AtCLE41/CLE44 generate similar phenotypic defects. In poplar, there are six CLE genes (PtTDIF1-4 and PtTDIF-like1-2) encoding two TDIF peptides (TDIF and TDIF-like peptide), which exhibit nearly same activities when exogenously applied to Arabidopsis seedlings. In this work, for each TDIF peptide, we chose two poplar CLE genes (PtTDIF2 and 3 for TDIF, and PtTDIF-like1-2 for TDIF-like peptide) to compare their in vivo effects in transgenic Arabidopsis. Our results showed that transgenic Arabidopsis lines overexpressing each individual PtTDIF gene exhibited dramatically distinct phenotypes associated with vascular development, demonstrating that TDIF motif is not the only functional determinant after genetic transformation. Moreover, we revealed that overexpressed poplar TDIFs enhanced the proliferation of (pro)cambial cells only in hypocotyls, but not in inflorescence stems by differentially regulating the transcriptional levels of WOX4 and WOX14 in these two tissues.

[Molecular epidemiological survey of hemoglobinopathies in Yongzhou area of Hunan province].

OBJECTIVE: To summarize the molecular epidemiology of hemoglobinopathies in Yongzhou area of Hunan province in order to provide a basis for making the guidelines of local thalassemia prevention program. METHODS: Two thousand and two samples (1001 couples) were randomly recruited based on demographic data and distribution of ethnic groups. All samples were subjected to full blood count and analysis of hemoglobin and 6 common alpha-thalassemia mutations. Known beta-thalassemia mutations were screened in samples with beta-thalassemia trait. The remaining samples with positive phenotype and unknown mutations were subjected to DNA sequence analysis. RESULTS: Two hundred and forty individuals were found to be carriers of hemoglobinopathic mutations, which included 6 common alpha-thalassemia deletions, 9 common beta-thalassemia mutations and 3 common structural hemoglobin variants. One hundred and seventy-four mutant alleles for alpha-thalassemia were detected, which gave a carrier rate of 8.69%, of which 0.1% was due to HbH disease. Seventy mutant alleles for beta-thalassemia were detected, which gave a carrier rate of 3.50%. Seven subjects (0.35%) were identified as carriers of hemoglobin variants. The overall carrier rate for hemoglobinopathic mutations was 12.54% based on detection of 251 hemoglobinopathy mutant alleles. The overall carrier rate for alpha- and beta-thalassemia among ethnic Yaos was 25.00%, which was significantly higher than that of ethnic Han Chinese (11.14%, P< 0.01). CONCLUSION: The prevalence and mutation spectrum of hemoglobinopathies in Yongzhou area has been delineated for the first time.

Gain-of-function analysis of poplar CLE genes in Arabidopsis by exogenous application and over-expression assays.

Among 50 CLE gene family members in the Populus trichocarpa genome, three and six PtCLE genes encode a CLE motif sequence highly homologous to Arabidopsis CLV3 and TDIF peptides, respectively, which potentially make them functional equivalents. To test and compare their biological activity, we first chemically synthesized each dodecapeptide and analysed itsi n vitro bioactivity on Arabidopsis seedlings. Similarly, but to a different extent, three types of poplar CLV3-related peptides caused root meristem consumption, phyllotaxis disorder, anthocyanin accumulation and failure to enter the bolting stage. In comparison, application of two poplar TDIF-related peptides led to root length promotion in a dose-dependent manner with an even stronger effect observed for poplar TDIF-like peptide than TDIF. Next, we constructed CaMV35S:PtCLE transgenic plants for each of the nine PtCLE genes. Phenotypic abnormalities exemplified by arrested shoot apical meristem and abnormal flower structure were found to be more dominant and severe in 35S:PtCLV3 and 35S:PtCLV3-like2 lines than in the 35S:PtCLV3-like line. Disordered vasculature was detected in both stem and hypocotyl cross-sections in Arabidopsis plants over-expressing poplar TDIF-related genes with the most defective vascular patterning observed for TDIF2 and two TDIF-like genes. Phenotypic difference consistently observed in peptide application assay and transgenic analysis indicated the functional diversity of nine poplar PtCLE genes under investigation. This work represents the first report on the functional analysis of CLE genes in a tree species and constitutes a basis for further study of the CLE peptide signalling pathway in tree development.

Identification and expression analysis of the LRR-RLK gene family in tomato (Solanum lycopersicum) Heinz 1706.

As the largest subfamily of receptor-like kinases (RLKs), leucine-rich repeat receptor-like kinases (LRR-RLKs) regulate the growth, development, and stress responses of plants. Through a reiterative process of sequence analysis and re-annotation, 234 LRR-RLK genes were identified in the genome of tomato (Solanum lycopersicum) 'Heinz 1706', which were further grouped into 10 major groups based on their sequence similarity. In comparison to the significant role of tandem duplication in the expansion process of this gene family in other species, only approximately 12% (29 out of 234) of SlLRR-RLK genes arose from tandem duplication. Using the multiple expectation maximization for motif elicitation (MEME) method, the motif composition and arrangement were found to be variably conserved within each SlLRR-RLK group, indicating their different extent of functional divergence. Expression profiling analyses by qRT-PCR data revealed that SlLRR-RLK genes were differentially expressed in various tomato organs and tissues, and some SlLRR-RLK genes exhibited preferential expression in fruits at distinct developmental stages, suggesting that SlLRR-RLK may take important roles in fruit development and ripening process. The results of this study provide an overview of the LRR-RLK gene family in tomato Heinz 1706, one important species of Solanaceae, and will be helpful for future functional analysis of this important protein family in fleshy fruit-bearing species.