Identification and characterization of cotton PHYTOCHROME-INTERACTING FACTORS in temperature-dependent flowering.

PHYTOCHROME INTERACTING FACTORS (PIFs) integrate light and temperature signs to control plant growth and development. However, little is known about PIFs in crop plants such as cotton. Here, we identified 68 PIF proteins and their coding genes from an allotetraploid and three diploid ancestors. Cotton PIFs contain typical ACTIVEPHYA-BINDING (APA) and ACTIVE PHYB-BINDING (APB) motifs by which they bind to phytochrome phyA and phyB, respectively, and have a BASIC HELIX-LOOP-HELIX (bHLH) domain and a nuclear localization sequence necessary for bHLH-type transcription factors. Bioinformatics analysis showed that the promoter of each PIF gene contains multiple cis-acting elements and that the evolution of cotton genomes probably underwent loss, recombination, and tandem replication. Further observations indicated that the sensitivity of cotton PIF expression to high temperature was significantly different from that to low temperature. We found that allotetraploid Gossypium hirsutum PIF4a (GhPIF4a) was induced by high temperature. GhPIF4a promotes flowering in cotton and Arabidopsis and binds to the promoter of GhFT (G. hirsutum FLOWERING LOCUS T), and binding increased with increasing temperature. Our work identifies the evolutionary and structural characteristics and functions of PIF family members in cotton.

Effect of 1-aminocyclopropane-1-carboxylic acid accumulation on Verticillium dahliae infection of upland cotton.

BACKGROUND: Verticillium wilt of cotton is a serious disease caused by the infection of soil borne fungus Verticillium dahliae Kleb, and the infection mechanisms may involve the regulation of phytohormone ethylene. The precursor of ethylene biosynthesis is 1-aminocyclopropane-1-carboxylic acid (ACC), whose biosynthesis in vivo depends on activation of ACC synthase (ACS). Here, we investigated how ACS activation and ACC accumulation affected the infection of V. dahliae strain Vd991 on cotton (Gossypium hirsutum L.) cultivar YZ1. RESULTS: Preliminary observations indicated that ACC applications reduced the disease incidence, disease index and stem vascular browning by impeding fungal biomass accumulation. Transcriptome and qRT-PCR data disclosed that Vd991 induced GhACS2 and GhACS6 expression. GhACS2- or GhACS6-overexpressing transgenic YZ1 lines were generated, respectively. In a Verticillium disease nursery with about 50 microsclerotia per gram of soil, these ACC-accumulated plants showed decreased disease indexes, stem fungal biomasses and vascular browning. More importantly, these transgenic plants decreased the green fluorescent protein-marked Vd991 colonization and diffusion in root tissues. Further, either ACC treatment or ACC-accumulating cotton plants activated salicylic acid (SA)-dependent resistance responses. CONCLUSIONS: The GhACS2- and GhACS6-dependent ACC accumulations enhanced the resistance of cotton to V. dahliae in a SA-dependent manner, and this lays a foundation for cotton resistance breeding.

Interaction between CASP8AP2 and ZEB2-CtBP2 Regulates the Expression of LEF1.

Low expression of CTBP2 and CASP8AP2 correlated with poor outcome and predicted risk of relapse in pediatric B-cell acute lymphoblastic leukemia (B-ALL). This study aimed to investigate the molecular mechanism by which CASP8AP2 regulates LEF1 expression by interacting with CtBP2 and ZEB2 in Acute lymphoblastic lymphoma (ALL). There was an interaction between CASP8AP2, ZEB2, and CtBP2, and then the interaction between CtBP2 and ZEB2 was observed after downregulating the expression of CASP8AP2. The wild type (containing the ZEB2 binding site) or mutant (containing a mutant binding site) LEF1 gene promoter sequence was inserted into the pGL3-basic plasmid, and a dual-luciferase reporter gene detection system was used to observe how CASP8AP2, ZEB2, and CtBP2 regulate the transcription of the LEF1 gene. We conclude that CASP8AP2, CtBP2, and ZEB2 can all bind to the LEF1 gene promoter region and reduce the luciferase activity of the LEF1 promoter. Meanwhile, the interaction of ZEB2 and the LEF1 promoter was significantly weakened after downregulation of CASP8AP2. Knockdown of CASP8AP2 in the 697 cell lines resulted in the significant upregulation of the mRNA expression levels of the stemness-related genes CD44, JAG1, and SALL4. In conclusion, CASP8AP2 is vital for the interaction between CtBP2 and ZEB2, inhibiting LEF1 and stemness-related genes expression ALL.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2022.2033369 .

[Functional polymorphism sites in non-coding regions of folate metabolism-related genes in the reproductive-aged population of Hubei Province].

Objective: To investigate the distribution of the functional polymorphisms in the non-coding regions of folate metabolism-related genes in the reproductive-aged population of Hubei Province. METHODS: Using Sanger sequencing, we examined the polymorphisms of the genes MTR (rs28372871 and rs1131450), MTRR (rs326119) and CBS (rs2850144) in 790 subjects before and during pregnancy from April 2020 to March 2021. We compared the distributions of the four loci between different populations. RESULTS: The distributions of the four genotypes of rs28372871, rs1131450, rs326119 and rs2850144 all conformed to the Hardy-Weinberg equilibrium (HWE). Statistically significant differences were observed in the polymorphism distribution of rs28372871 between Hubei and Jiangsu (P < 0.05), in that of rs1131450 between Hubei and Shanghai (P < 0.05), and in that of rs2850144 between Hubei and Yazd, Iran (P < 0.01). CONCLUSIONS: This was the first investigation on the distribution of MTR, MTRR and CBS gene polymorphisms in the reproductive-aged population of Hubei Province. The effects of the functional loci in both encoding and non-coding regions of folate metabolism-related genes have to be comprehensively considered so as to formulate an appropriate folate-supplementary protocol.

[Using Immunohistochemical Markers and Clinicopathological Factors to Predict the Prognostic Survival of Different Types of Endometrial Cancer Recurrence].

OBJECTIVE: To probe for factors that can be used effectively to predict the prognostic survival of patients with endometrial cancer recurrence. METHODS: The clinicopathological data of 473 patients with stage Ⅰ to Ⅲ endometrial cancer who underwent standard surgical treatment from October 2013 to May 2019 were retrospectively collected, and post-operative recurrence of the patients were followed up. Overall recurrence includes local recurrence and poor prognosis recurrence. The endpoint indicators of this study are the recurrence-free survival (RFS) and overall survival (OS) of patients with overall recurrence, local recurrence, and poor prognosis recurrence (PPR). The Kaplan-Meier survival curve was used to evaluate the OS and RFS of patients. Cox proportional-hazards model was used to identify factors affecting the prognostic survival of patients with endometrial cancer recurrence. RESULTS: Among the 473 patients, 406 did not experience recurrence. A total of 67 patients, accounting for 14.2%, had recurrence. Among them, 27 had local recurrence, accounting for 5.7%, while 40 had poor prognosis recurrence, accounting for 8.5%. The median follow-up time of patients with recurrence was 38 months. The survival curve showed that the RFS and OS of the patients in the recurrence-free group remained unchanged, while the patients in the recurrence group, regardless of whether they had overall recurrence, local recurrence or PPR, experienced a decrease in RFS and OS( P<0.001). The overall 3-year OS rate of patients with recurrence was 44.8%, the median survival time was 29 months, and the median recurrence time was 17 months. The 3-year OS rate of patients in the recurrence-free group was 98.8%, and the median survival time was 40 months; the 3-year OS rate of patients with local recurrence was 59.3%, the median survival time was 27 months, and the median recurrence time was 15 months. The 3-year OS rate of patients with PPR was only 35.0%, the median survival time was 22 months, and the median recurrence time was 10 months. The results of multivariate Cox regression analysis showed that, for overall recurrence patients, FIGO stage Ⅲ (hazard ratio ( HR)=3.432, P=0.005), increased expression of K-i67 ( HR=1.015, P=0.025), and decreased expression of estrogen receptor (ER) ( HR=0.985, P=0.005) are independent factors for the decline in RFS, FIGO stage Ⅲ ( HR=4.918, P=0.005) and the decreased expression of progesterone receptor (PR) ( HR=0.977, P=0.003) are independent factors for the decrease in OS. For patients with local recurrence, special pathological types ( HR=2.545, P=0.049) and increased expression of Ki-67 ( HR=1.024, P=0.033) are independent factors influencing the decrease in RFS, while decreased expression of PR ( HR=0.973, P=0.009) is an independent risk factor for decreased OS. For patients with PPR, FIGO stage Ⅲ ( HR=5.977, P=0.002) and decreased ER expression ( HR=0.984, P=0.023) are independent risk factors for the decline in RFS, while FIGO stage Ⅲ ( HR=10.098, P=0.001) is an independent factor influencing the decline of OS. CONCLUSION: FIGO stage Ⅲ, increased Ki-67 expression, and decreased ER expression can increase patients' risk of postoperative recurrence, and FIGO stage Ⅲ and decreased expression of PR can increase the risk of death in patients with recurrence.

The structural basis of the dominant negative phenotype of the Gαi1ß1γ2 G203A/A326S heterotrimer.

AIM: Dominant negative mutant G proteins have provided critical insight into the mechanisms of G protein-coupled receptor (GPCR) signaling, but the mechanisms underlying the dominant negative characteristics are not completely understood. The aim of this study was to determine the structure of the dominant negative Gαi1ß1γ2 G203A/A326S complex (Gi-DN) and to reveal the structural basis of the mutation-induced phenotype of Gαi1ß1γ2. METHODS: The three subunits of the Gi-DN complex were co-expressed with a baculovirus expression system. The Gi-DN heterotrimer was purified, and the structure of its complex with GDP was determined through X-ray crystallography. RESULTS: The Gi-DN heterotrimer structure revealed a dual mechanism underlying the dominant negative characteristics. The mutations weakened the hydrogen bonding network between GDP/GTP and the binding pocket residues, and increased the interactions in the Gα-Gßγ interface. Concomitantly, the Gi-DN heterotrimer adopted a conformation, in which the C-terminus of Gαi and the N-termini of both the Gß and Gγ subunits were more similar to the GPCR-bound state compared with the wild type complex. From these structural observations, two additional mutations (T48F and D272F) were designed that completely abolish the GDP binding of the Gi-DN heterotrimer. CONCLUSION: Overall, the results suggest that the mutations impede guanine nucleotide binding and Gα-Gßγ protein dissociation and favor the formation of the G protein/GPCR complex, thus blocking signal propagation. In addition, the structure provides a rationale for the design of other mutations that cause dominant negative effects in the G protein, as exemplified by the T48F and D272F mutations.

Tracing back of relapse clones by Ig/TCR gene rearrangements reveals complex patterns of recurrence in pediatric acute lymphoblastic leukemia.

INTRODUCTION: Relapse remained the major obstacle to improving the prognosis of children with acute lymphoblastic leukemia (ALL). This study aimed to investigate the changing patterns of Ig/TCR gene rearrangements between diagnosis and relapse and the clinical relevance and to explore the mechanism of leukemic relapse. METHODS: Clonal Ig/TCR gene rearrangements were screened by multiplex PCR amplification in 85 paired diagnostic and relapse bone marrow (BM) samples from children with ALL. The new rearrangements presented at relapse were quantitatively assessed by the RQ-PCR approach targeting the patient-specific junctional region sequence in 19 diagnostic samples. The relapse clones were further back-traced to diagnostic and follow-up BM samples from 12 patients. RESULTS: Comparison of Ig/TCR gene rearrangements between diagnosis and relapse showed that 40 (57.1%) B-ALL and 5 (33.3%) T-ALL patients exhibited a change from diagnosis to relapse, and 25 (35.7%) B-ALL patients acquired new rearrangements at relapse. The new relapse rearrangements were present in 15 of the 19 (78.9%) diagnostic samples as shown by RQ-PCR, with a median level of 5.26 × 10-2 . The levels of minor rearrangements correlated with B immunophenotype, WBC counts, age at diagnosis, and recurrence time. Furthermore, back-tracing rearrangements in 12 patients identified three patterns of relapse clone dynamics, which suggested the recurrence mechanisms not only through clonal selection of pre-existing subclones but also through an ongoing clonal evolution during remission and relapse. CONCLUSION: Backtracking Ig/TCR gene rearrangements in relapse clones of pediatric ALL revealed complex patterns of clonal selection and evolution for leukemic relapse.

Activation of 1-Aminocyclopropane-1-Carboxylic Acid Synthases Sets Stomatal Density and Clustered Ratio on Leaf Epidermis of Arabidopsis in Response to Drought.

The adjustment of stomatal density and clustered ratio on the epidermis is the important strategy for plants to respond to drought, because the stoma-based water loss is directly related to plant growth and survival under drought conditions. But the relevant adjustment mechanism still needs to be explored. 1-Aminocyclopropane-1-carboxylate (ACC) is disclosed to promote stomatal development, while in vivo ACC levels depend on activation of ACC synthase (ACS) family members. Based on the findings of ACS expression involving in drought response and several ACS activity inhibitors reducing stomatal density and cluster in drought response, here we examined how ACS activation is involved in the establishment of stomatal density and cluster on the epidermis under drought conditions. Preliminary data indicated that activation of ACS2 and/or ACS6 (ACS2/6) increased stomatal density and clustered ratio on the Arabidopsis leaf epidermis by accumulating ACC under moderate drought, and raised the survival risk of seedlings under escalated drought. Further exploration indicated that, in Arabidopsis seedlings stressed by drought, the transcription factor SPEECHLESS (SPCH), the initiator of stomatal development, activates ACS2/6 expression and ACC production; and that ACC accumulation induces Ca2+ deficiency in stomatal lineage; this deficiency inactivates a subtilisin-like protease STOMATAL DENSITY AND DISTRIBUTION 1 (SDD1) by stabilizing the inhibition of the transcription factor GT-2 Like 1 (GTL1) on SDD1 expression, resulting in an increases of stomatal density and cluster ratio on the leaf epidermis. This work provides a novel evidence that ACS2/6 activation plays a key role in the establishment of stomatal density and cluster on the leaf epidermis of Arabidopsis in response to drought.