The regulatory mechanisms of pollen development have potential value for applications in agriculture, such as better understanding plant reproductive regularity. Pollen-specific promoters are of vital importance for the ectopic expression of functional genes associated with pollen development in plants. However, there is a limited number of successful applications using pollen-specific promoters in genetic engineering for crop breeding and hybrid generation. Our previous work led to the identification and isolation of the OsSUT3 promoter from rice. In this study, to analyze the effects of different putative regulatory motifs in the OsSUT3 promoter, a series of promoter deletions were fused to a GUS reporter gene and then stably introduced into rice and Arabidopsis. Histochemical GUS analysis of transgenic plants revealed that p385 (from −385 to −1) specifically mediated maximal GUS expression in pollen tissues. The S region (from −385 to −203) was the key region for controlling the pollen-specific expression of a downstream gene. The E1 (−967 to −606), E2 (−202 to −120), and E3 (−119 to −1) regions enhanced ectopic promoter activity to different degrees. Moreover, the p385 promoter could alter the expression pattern of the 35S promoter and improve its activity when they were fused together. In summary, the p385 promoter, a short and high-activity promoter, can function to drive pollen-specific expression of transgenes in monocotyledon and dicotyledon transformation experiments.

The mulch film (MF) management model of the agricultural field affects the physical and chemical properties of soil (PCPS) and the structure of the microorganism community; however, studies on the relationship between the rhizosphere microorganism community structure and the thickness of MF are still limited. To understand the interactions among the MF thickness, PCPS, and rhizosphere microorganism, a study was conducted by using an integrated metagenomic strategy, where tobacco rhizosphere soil was treated with four commonly representative and used thicknesses of MFs (0.004, 0.006, 0.008, and 0.010 mm) in Yunnan laterite. The results showed that agronomic traits such as the tobacco plant height (TPH), leaf number (LN), fresh leaf weight (FLW), and dry leaf weight (DLW) were significantly (p < 0.01) improved in the field mulched with the thickest film (0.010 mm) compared with the exposed field (CK), and there was a 6.81 and 5.54% increase in the FLW and TPH, separately. The correlation analyses revealed a significant positive correlation of the MF thickness with the soil water content (SWC), soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), and available phosphorus (AP; all p < 0.01), while the MF thickness was negatively correlated with the soil temperature (ST; p < 0.01). In addition, the community structure of the rhizosphere soil bacteria was significantly changed overall by the MF thickness, which also interfered with the function of the rhizosphere soil bacteria. The correlation analyses also showed that the abundance of Bradyrhizobium and Nitrospira was positively correlated with the MF thickness, while the abundance of Sphinsinomonas and Massilia was negatively correlated with it. This indicated that with the increase of the MF thickness, the ability of the rhizosphere soil to utilize N and remove harmful molecules was strengthened, while the capacity of the rhizosphere soil to degrade pollutants was greatly reduced. These findings provide additional insights into the potential risks of the application of different thicknesses of MFs, particularly concerning the PCPS and soil microbial communities.

‘Dianheyou615’ (DHY615) is an elite Dian (D1)-type hybrid japonica rice variety, renowned for its high yield, exceptional grain quality, and unique adaptability to both irrigated and rainfed conditions in the Yungui Plateau of southwestern China. However, the genetic mechanisms underlying the agronomic performance of the D1-type hybrid japonica rice remain unclear. In this study, a comprehensive analysis of ‘DHY615’’s agronomic performance, genetic genealogy, and molecular genetic foundation was conducted to dissect its desirable traits for upland rainfed cultivation across diverse ecological environments. The main findings indicate that ‘DHY615’ possesses 6432 heterozygous SNPs, with 57.48% and 14.43% located in the promoter and coding regions, respectively, potentially affecting key phenotypic traits. High-impact SNPs variants and numerous well-known functional genes were identified, such as OsAAP6, GS3, Sd1, Rf1, BADH2, BPh14, Rymv1, OsFRO1, NRT1.1B, SKC1, OsNCED2, and qUVR-10, which are likely linked to traits including plant architecture, grain yield, grain quality, and resistance to various biotic and abiotic stresses (e.g., disease, cold, drought, salt, high iron, and high UV radiation). Notably, ‘Nan615’ harbors a greater number of functional allele variants compared to ‘H479A’, which potentially explaining its superior grain yield and remarkable adaptability. This study offers novel and valuable insights into the molecular genetic foundation of the plateau D1-type hybrid japonica rice, underscoring its potential for sustainable rice production across diverse ecological zones, especially with its unparalleled high-altitude adaptability to rainfed upland planting.

Sucrose transport and starch accumulation are crucial carbohydrate metabolic processes in rice, playing essential roles during late pollen development to ensure pollen maturation, fertility and high grain production. However, the molecular mechanisms regulating sucrose transport and starch accumulation during rice pollen development remain elusive. In this study, we bred and characterized a semi‐fertile rice pollen variant, sfp10 , which is derived from highland terraced red rice from Yunnan, China. This variant showed insufficient starch accumulation in pollen, reduced pollen fertility and decreased seed setting compared to the wild type. Using map‐based cloning, CRISPR/Cas9 mutagenesis and gene complementation, the OsSUT3 gene, which causes the sfp10 variant, was shown to encode a sucrose transporter (SUT) that transports sucrose into pollen for starch synthesis, ensuring pollen viability and fertility. Additionally, transcriptome analysis identified OsWRKY15, a WRKY transcription factor that exhibits a highly similar spatiotemporal expression pattern to OsSUT3 in late‐developing panicles. Yeast one‐hybrid, EMSA, dual‐luciferase reporter and ChIP‐seq assays demonstrated that OsWRKY15 directly binds to the promoter region of OsSUT3 and upregulates its expression. Mutation of OsWRKY15 significantly reduced OsSUT3 expression and impaired pollen fertility and seed setting and these defects were further exacerbated in the wrky15/OsSUT3‐KO double‐knockout lines, while OsSUT3 overexpression in the wrky15 background significantly rescued pollen fertility and seed setting. These findings demonstrate that the OsWRKY15‐OsSUT3 regulatory module is essential for sucrose transport and starch accumulation during late pollen development in rice, providing new insights into the transcriptional regulation of carbon allocation to anthers for rice fertility and grain production.