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The basic leucine zipper (bZIP) transcription factor (TF) family is one of the biggest TF families identified so far in the plant kingdom, functioning in diverse biological processes including plant growth and development, signal transduction, and stress responses. For Perilla frutescens, a novel oilseed crop abundant in polyunsaturated fatty acids (PUFAs) (especially α-linolenic acid, ALA), the identification and biological functions of bZIP members remain limited. In this study, 101 PfbZIPs were identified in the perilla genome and classified into eleven distinct groups (Groups A, B, C, D, E, F, G, H, I, S, and UC) based on their phylogenetic relationships and gene structures. These PfbZIP genes were distributed unevenly across 18 chromosomes, with 83 pairs of them being segmental duplication genes. Moreover, 78 and 148 pairs of orthologous bZIP genes were detected between perilla and Arabidopsis or sesame, respectively. PfbZIP members belonging to the same subgroup exhibited highly conserved gene structures and functional domains, although significant differences were detected between groups. RNA-seq and RT-qPCR analysis revealed differential expressions of 101 PfbZIP genes during perilla seed development, with several PfbZIPs exhibiting significant correlations with the key oil-related genes. Y1H and GUS activity assays evidenced that PfbZIP85 downregulated the expression of the PfLPAT1B gene by physical interaction with the promoter. PfLPAT1B encodes a lysophosphatidate acyltransferase (LPAT), one of the key enzymes for triacylglycerol (TAG) assembly. Heterogeneous expression of PfbZIP85 significantly reduced the levels of TAG and UFAs (mainly C18:1 and C18:2) but enhanced C18:3 accumulation in both seeds and non-seed tissues in the transgenic tobacco lines. Furthermore, these transgenic tobacco plants showed no significantly adverse phenotype for other agronomic traits such as plant growth, thousand seed weight, and seed germination rate. Collectively, these findings offer valuable perspectives for understanding the functions of PfbZIPs in perilla, particularly in lipid metabolism, showing PfbZIP85 as a suitable target in plant genetic improvement for high-value vegetable oil production. [ABSTRACT FROM AUTHOR]

Phytophthora root rot is a devastating disease of soybean caused by Phytophthora sojae. However, the resistance mechanism is not yet clear. Our previous studies have shown that GmAP2 enhances sensitivity to P. sojae in soybean, and GmMYB78 is downregulated in the transcriptome analysis of GmAP2-overexpressing transgenic hairy roots. Here, GmMYB78 was significantly induced by P. sojae in susceptible soybean, and the overexpressing of GmMYB78 enhanced sensitivity to the pathogen, while silencing GmMYB78 enhances resistance to P. sojae, indicating that GmMYB78 is a negative regulator of P. sojae. Moreover, the jasmonic acid (JA) content and JA synthesis gene GmAOS1 was highly upregulated in GmMYB78-silencing roots and highly downregulated in overexpressing ones, suggesting that GmMYB78 could respond to P. sojae through the JA signaling pathway. Furthermore, the expression of several pathogenesis-related genes was significantly lower in GmMYB78-overexpressing roots and higher in GmMYB78-silencing ones. Additionally, we screened and identified the upstream regulator GmbHLH122 and downstream target gene GmbZIP25 of GmMYB78. GmbHLH122 was highly induced by P. sojae and could inhibit GmMYB78 expression in resistant soybean, and GmMYB78 was highly expressed to activate downstream target gene GmbZIP25 transcription in susceptible soybean. In conclusion, our data reveal that GmMYB78 triggers soybean sensitivity to P. sojae by inhibiting the JA signaling pathway and the expression of pathogenesis-related genes or through the effects of the GmbHLH122-GmMYB78-GmbZIP25 cascade pathway. [ABSTRACT FROM AUTHOR]

Leaf senescence is the terminal stage of leaf development, and its initiation and progression are closely controlled by the integration of a myriad of endogenous signals and environmental stimuli. It has been documented that WRKY transcription factors (TFs) play essential roles in regulating leaf senescence, yet the molecular mechanism of WRKY-mediated leaf senescence still lacks detailed elucidation in crop plants. In this study, we cloned and identified a tobacco WRKY TF gene, designated NtWRKY70b, acting as a positive regulator of natural leaf senescence. The expression profile analysis showed that NtWRKY70b transcript levels were induced by aging and hydrogen peroxide (H2O2) and downregulated upon hydrogen sulfide (H2S) treatment. The physiological and biochemical assays revealed that overexpression of NtWRKY70b (OE) clearly promoted leaf senescence, triggering increased levels of reactive oxygen species (ROS) and decreased H2S content, while disruption of NtWRKY70b by chimeric repressor silencing technology (SRDX) significantly delayed the onset of leaf senescence, leading to a decreased accumulation of ROS and elevated concentration of H2S. The quantitative real-time PCR analysis showed that the expression levels of various senescence-associated genes and ROS biosynthesis-related genes (NtRbohD and NtRbohE) were upregulated in OE lines, while the expression of H2S biosynthesis-related genes (NtDCD and NtCYSC1) were inhibited in OE lines. Furthermore, the Yeast one-hybrid analysis (Y1H) and dual luciferase assays showed that NtWRKY70b could directly upregulate the expression of an ROS biosynthesis-related gene (NtRbohD) and a chlorophyll degradation-related gene (NtPPH) by binding to their promoter sequences. Accordingly, these results indicated that NtWYKY70b directly activated the transcript levels of NtRbohD and NtPPH and repressed the expression of NtDCD and NtCYCS1, thereby promoting ROS accumulation and impairing the endogenous H2S production, and subsequently accelerating leaf aging. These observations improve our knowledge of the regulatory mechanisms of WRKY TFs controlling leaf senescence and provide a novel method for ensuring high agricultural crop productivity via genetic manipulation of leaf senescence in crops. [ABSTRACT FROM AUTHOR]

Phytophthora root and stem rot of soybean (Glycine max), caused by the oomycete Phytophthora sojae, is an extremely destructive disease worldwide. In this study, we identified GmEIL1, which encodes an ethylene‐insensitive3 (EIN3) transcription factor. GmEIL1 was significantly induced following P. sojae infection of soybean plants. Compared to wild‐type soybean plants, transgenic soybean plants overexpressing GmEIL1 showed enhanced resistance to P. sojae and GmEIL1‐silenced RNA‐interference lines showed more severe symptoms when infected with P. sojae. We screened for target genes of GmEIL1 and confirmed that GmEIL1 bound directly to the GmERF113 promoter and regulated GmERF113 expression. Moreover, GmEIL1 positively regulated the expression of the pathogenesis‐related gene GmPR1. The GmEIL1‐regulated defence response to P. sojae involved both ethylene biosynthesis and the ethylene signalling pathway. These findings suggest that the GmEIL1‐GmERF113 module plays an important role in P. sojae resistance via the ethylene signalling pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: Mosquitoes are vectors of various diseases, posing significant health threats worldwide. Chemical pesticides, particularly pyrethroids like deltamethrin, are commonly used for mosquito control, but the emergence of resistant mosquito populations has become a concern. In the deltamethrin‐resistant (DR) strain of Culex pipiens pallens, the highly expressed cytochrome P450 9 J34 (CYP9J34) gene is believed to play a role in resistance, yet the underlying mechanism remains unclear. RESULTS: Quantitative polymerase chain reaction with reverse transcription (qRT–PCR) analysis revealed that the expression of CYP9J34 was 14.6‐fold higher in DR strains than in deltamethrin‐susceptible (DS) strains. The recombinant production of CYP9J34 protein of Cx. pipiens pallens showed that the protein could directly metabolize deltamethrin, yielding the major metabolite 4′‐OH deltamethrin. Through dual luciferase reporter assays and RNA interference, the transcription factor homeobox protein B‐H2‐like (B‐H2) was identified to modulate the expression of the CYP9J34 gene, contributing to mosquito resistance to deltamethrin. CONCLUSIONS: Our findings demonstrate that the CYP9J34 protein could directly degrade deltamethrin, and the transcription factor B‐H2 could regulate CYP9J34 expression, influencing the resistance of mosquitoes to deltamethrin. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Simple Summary: This investigation delves into the intricate mechanisms of autophagy-dependent cisplatin resistance in bladder cancer. Our primary objective is to unveil the precise role of SIRT1, a deacetylase enzyme, in orchestrating cisplatin resistance through autophagic pathways in the cisplatin-resistant T24/DDP cell line. The findings demonstrate that inhibiting autophagy diminishes drug resistance, while SIRT1 overexpression intensifies this resistance by stimulating autophagy. Significantly, silencing SIRT1 elevates Beclin1 acetylation, suppressing autophagy and attenuating cisplatin resistance. This nuanced understanding of SIRT1-mediated cisplatin resistance not only furthers our theoretical foundation, but also furnishes potential therapeutic targets. Autophagy-dependent cisplatin resistance poses a challenge in bladder cancer treatment. SIRT1, a protein deacetylase, is involved in autophagy regulation. However, the precise mechanism through which SIRT1 mediates cisplatin resistance in bladder cancer via autophagy remains unclear. In this study, we developed a cisplatin-resistant T24/DDP cell line to investigate this mechanism. The apoptosis rate and cell viability were assessed using flow cytometry and the CCK8 method. The expression levels of the relevant RNA and protein were determined using RT-qPCR and a Western blot analysis, respectively. Immunoprecipitation was utilized to validate the interaction between SIRT1 and Beclin1, as well as to determine the acetylation level of Beclin1. The findings indicated the successful construction of the T24/DDP cell line, which exhibited autophagy-dependent cisplatin resistance. Inhibiting autophagy significantly reduced the drug resistance index of these cells. The T24/DDP cell line showed a high SIRT1 expression level. The overexpression of SIRT1 activated autophagy, thereby further promoting cisplatin resistance in the T24/DDP cell line. Conversely, inhibiting autophagy counteracted the cisplatin-resistance-promoting effects of SIRT1. Silencing SIRT1 led to increased acetylation of Beclin1, the inhibition of autophagy, and a reduction in the cisplatin resistance of the T24/DDP cell line. Introducing a double mutation (lysine 430 and 437 to arginine, 2KR) in Beclin-1 inhibited acetylation and activated autophagy, effectively reversing the decreased cisplatin resistance resulting from SIRT1 silencing. In summary, our study elucidated that SIRT1 promotes cisplatin resistance in human bladder cancer T24 cells through Beclin1-deacetylation-mediated autophagy activation. These findings suggest a potential new strategy for reversing cisplatin resistance in bladder cancer. [ABSTRACT FROM AUTHOR]

Largemouth bass (LMB; Micropterus salmoides) is an economically consequential piscine species spanning North America, Europe, and China. Elevated nitrite concentrations in aquatic environments cause significant physiological changes in fish, including stunted growth, appetite changes, reduced feed intake, and impaired oxygen transport, collectively affecting overall fish health. This study embarked on uncovering the molecular mechanisms underscoring the influence of various nitrite concentrations (0 mg/L, 400 mg/L, 600 mg/L, and 600 mg/L followed by recovery in nitrite-free water) on LMB, leveraging transcriptomics and metabolomics. Our findings revealed that a nitrite exposure of 400/600 mg/L may incite temporary, recoverable damage to the spleen, heart, and gills, but potentially enduring, irreversible hepatic pathologies. The spleen emerged as the most vulnerable organ to nitrite-induced deleterious impacts, causing acute, reversible damage and widespread apoptosis. Nitrite reprogramed splenocyte gene expressions, and prompted apoptosis, autophagy, and changes in metabolic pathways. It also triggered cell-type transitions and promoted adhesion-related gene expressions, as well as inhibited nucleotide metabolism and cell cycle progression. Notably, the immune cell repertoire within the spleen was affected by different nitrite concentrations, possibly linking to nitrite-induced spleen tissue impairment. Following the construction of a LMB protein–protein interaction (PPI) network, several pivotal genes uniquely expressed in distinct nitrite concentrations were identified, such as hdac4 , hdac5 , and brg1 in the N2 group (400 mg/L), hdac1 , hells , and nccrp1 in the N3 group (600 mg/L), and Actr1 , brd4 , atf7a , and kat2b in the N4 group (600 mg/L recovery). The LMB spleen transcriptome was most profoundly influenced in the N3 group. Applying the MCODE algorithm for network module segmentation, we discerned eight MCODE subnetworks. Detailed analyses of these subnetworks shed light on their core functional pathways and pivotal genes. In particular, the MCODE1 core network implicated mainly Notch-HLH transcription, histone deacetylation, and protein deacetylation pathways, with pivotal genes such as ESRRGB , ATF7A , JDP2A , BRD4 , and THRB. Metabolomic analysis results paralleled those of transcriptomic examination, corroborating analogous metabolic pathway alterations. This study holds substantial implications for comprehending the toxicological impact of nitrite on economically important fish species like LMB, and provides insights for refining aquaculture practices to minimize this toxicity. • High nitrite concentrations cause reversible damage to largemouth bass (LMB) organs, potentially irreversible liver damage. • Nitrite reprograms gene expression in the LMB spleen, causing apoptosis, autophagy, and metabolic pathway changes. • Nitrite concentrations affect immune repertoire in the LMB spleen. • Network module segmentation uncovers core functional pathways and pivotal genes regarding nitrite treatment. • Metabolomic and transcriptomic analyses reveal similar metabolic pathway alterations. [ABSTRACT FROM AUTHOR]

The myometrium, composed of the inner circular muscle (CM) and outer longitudinal muscle (LM), is crucial in establishing and maintaining early pregnancy. However, the molecular mechanisms involved are not well understood. In this study, we identified the transcriptomic features of the CM and LM collected from the mesometrial (M) and anti-mesometrial (AM) sides of the pig uterus on day 18 of pregnancy during the placentation initiation phase. Some genes in the cellular zinc ion level regulatory pathways (MT-1A , MT-1D , MT-2B , SLC30A2 , and SLC39A2) were spatially and highly enriched in uterine CM at the mesometrial side. In addition, the histone modification profiles of H3K27ac and H3K4me3 in uterine CM and LM collected from the mesometrial side were characterized. Genomic regions associated with the expression of genes regulating the cellular zinc ion level were detected. Moreover, six highly linked variants in the H3K27ac-enriched region of the pig SLC30A2 gene were identified and found to be significantly associated with the total number born at the second parity (P < 0.05). In conclusion, the genes in the pathways of cellular zinc homeostasis and their regulatory elements identified have implications for pig reproduction trait improvement and warrant further investigations. • The myometrium includes the circular muscle (CM) and longitudinal muscle (LM) layers. • Genes in the cellular zinc homeostasis pathway were highly enriched in pig uterine CM. • Genomic regions related to gene expression that regulate zinc ion levels were detected. • Six variants in the H3K27ac-enriched region upstream of the SLC30A2 gene were associated with litter size in pigs. [ABSTRACT FROM AUTHOR]