This study assessed the responses of wild-type (WT) and transgenic Arabidopsis expressing seven combinations of maize (Zea mays) genes phosphoenolpyruvate carboxylase (pepc), pyruvate phosphate dikinase (ppdk), and NADP-malic enzyme (nadp-me) to high light. Our results showed that the net CO₂ assimilation rate (P_n) and shoot dry weight of four of the transgenic Arabidopsis genotypes were significantly different from those of WT under high-light treatment, being in the order of Zmpepc+Zmppdk+Zmnadp-me (PC-K-M) > Zmpepc+Zmppdk (PC-K) > Zmpepc (PC), Zmpepc+Zmnadp-me (PC-M) > WT. The other genotypes did not differ from WT. This indicated that Zmpepc was essential for maintaining high photosynthetic performance under high light, Zmppdk had a positive synergistic effect on Zmpepc, and the combination of all three genes had the greatest synergistic effect. These four genotypes also maintained higher photosystem II (PSII) activity (K-phase, J-phase, RC/CSm), electron transfer capacity (J-phase), and photochemical efficiency (TRo/ABS), and accumulated less reactive oxygen species (O₂·⁻, H₂O₂) and suffered less damage to the membrane system (MDA) than WT under high light. Collectively, PC, PC-K, PC-M, and PC-K-M used most of the absorbed energy for CO₂ assimilation through a significantly higher P_n, which reduced the generation of excess electrons in the photosynthetic apparatus, thereby reducing damage to the membrane system and PSII. This ultimately resulted in improved high-light tolerance. P_n was the main reason for the significant difference in the high-light tolerance of the four genotypes. Joint expression of the three maize genes may be of great value in the genetic improvement of high-light tolerance in C₃ crops.

Although wheat cultivars and yields in Henan Province have improved continuously, there have been no systematic reports on breeding improvement in recent decades. This study aims to elucidate the genetic basis of these wheat cultivars and summarize their breeding advances across four breeding periods. A total of 351 landraces and 265 cultivars from Henan Province were used in selective sweep studies and planted at five locations within the province in 2016 − 2017, 2017 − 2018, and 2018 − 2019 for genome-wide association studies. Candidate genes were identified through differential expression, Gene Ontology (GO) annotation, gene homology, and haplotype analyses. The results demonstrated that 263 known genes with selection signals were associated with yield, quality, and resistance traits. Of the quantitative trait loci identified, 51 genes had been previously reported, whereas 252 genes were novel candidates; among these, 80 genes and 50 loci contributed to the improvement of 12 traits, such as plant height. Twelve key candidate genes were verified by quantitative reverse transcription PCR (qRT-PCR). Superior haplotypes of 24 and 164 genes, respectively, explain cultivar climate adaptation and are available for future breeding. Conversely, analyses of superior haplotypes in cultivars from the 2000s onward suggest that parental selection should consider a broader range of germplasm resources, rather than just recent accessions. The transmission of superior haplotypes in four varietal pedigrees revealed the pyramiding in elite cultivars. This study provides a genetic basis for wheat improvement and offers guidance for future genetic improvement.

Breeding wheat varieties with a high nitrogen use efficiency (NUE) reduces both production costs and threats to the ecological environment. Here, using candidate-gene and genome-wide association studies, we identify TaNPF7.6-A1 as a positive regulator of NUE in wheat. A widely conserved polymorphism in the coding region of TaNPF7.6-A1 produces allele TaNPF7.6-A1^mod with a higher transcription level and nitrate transport activity than TaNPF7.6-A1^lan, resulting in a greater NUE. We also reveal the mechanism by which TaEIL3-TaJAZ1-TaNPF7.6-A1 regulates NUE in wheat. TaNPF7.6-A1^mod interacts more strongly with TaJAZ1 than TaNPF7.6-A1^lan and promotes the retention of nuclear-localized TaJAZ1 in the cytoplasm. TaJAZ1 interacts with TaEIL3 and represses TaEIL3, binding to the TaNPF7.6-A1^mod promoter, influencing allele expression and causing phenotypic differences. TaNPF7.6-A1^mod also shows significant geographical distribution aggregation globally and undergoes continuous positive selection during the breeding process. Overall, this study provides molecular and evolutionary insights into the regulation of NUE.

Introduction: Magnesium transporters (MGTs) are crucial for Mg²⁺ uptake, transport, and storage. Although MGT family has been characterized in many plants, genome-wide identification and functional analysis of MGTs in wheat ( Triticum aestivum L .) remain largely unclear. Methods: In this study, we identified wheat MGT genes using comparative genomics, and further analyzed their phylogeny, gene structure, conserved motifs, subcellular localization, gene duplication, protein–protein interactions, and expression patterns. Tissue-specific expression was verified by qRT‑PCR. Results: A total of 63 TaMGT genes were identified and classified into MRS2, CorA, and NIPA subfamilies. Most TaMGT proteins were predicted to target membrane systems. A total of 200 magnesium transporter genes were found considered to be generated by gene duplication events, and 1045 interacting proteins were predicted. TaMGT genes were highly expressed in flowering anthers. qRT‑PCR confirmed that 24 TaMRS2 genes exhibited obvious tissue specificity, with higher expression in leaves, stems, and spikes than in roots. Discussion: This study systematically reveals the evolutionary characteristics and functional differentiation of wheat MGT genes, and supports their important roles in reproductive growth. Our results provide a theoretical basis for further functional studies of magnesium transporters in wheat.