Cryptochromes (CRYs) are blue light receptors that regulate various plant responses. CRYs exist in the dark as an inactive monomer, which absorbs photons and undergo conformational changes and oligomerization. Light alters the affinity between CRYs and interacting proteins, thereby regulating the transcription or stability of photoresponsive proteins to modulate plant growth and development. A recent study has discovered a sophisticated mechanism of CRY2 function, which is not only ‘activated’ by blue light but also by dark signals, thus constructing a more energy-efficient mode of light and dark signal dependent photoreceptor signaling. The authors found that CRY2 can inhibit cell division in root meristematic tissue even in the dark, regulate root elongation and growth, and control the expression of a large number of genes. FL1 and FL3 bind to the chromatin of cell division genes to promote their transcription. It is interesting that only the CRY2 monomer in the dark interacts with FL1/FL3, thereby inhibiting FL1/FL3 to promote root elongation, while blue light releases this inhibitory effect. This discovery reshapes people’s understanding of light receptors, and provides a new perspective for understanding plant perception and response to different signals to regulate growth and adaptability. Moreover, it is highly enlightening for a deeper understanding of sophisticated gene regulation.

Seed desiccation is a key physiological process during plant seed maturation, directly affecting seed moisture content, storage, and quality. In agricultural practice, the kernel dehydration rate (KDR) is a critical determinant of seed water content at harvest and seed quality for mechanical harvesting. Over the past decades, although physiological changes in transcriptome and hormone levels have been linked to seed dehydration, little progress for underlying mechanisms has been achieved. A recent study identified a QTL located in a non-coding region, named qKDR1, which regulates the dehydration rate during maize seed maturation. By recruiting the transcription factors ZmMYBST1 and ZmMYBR43, it suppresses the transcription of the micropeptide-encoding gene RPG upstream of qKDR1, leading to reduced expression of RPG. The encoded micropeptide, microRPG1, regulates the KDR through the ethylene signaling pathway, highlighting its potential in crop breeding and agricultural practices. This study advances our understanding of the molecular mechanisms underlying seed desiccation and provides theoretical support for breeding crops with faster KDR and improved storage qualities.

Strigolactone (SL) is a novel plant hormone that regulates important growth and developmental processes such as plant branching. In rice, the SL receptor D14 perceives SL signals, binds with the F-box protein D3, and recruits the transcriptional repressor D53, inducing the ubiquitination and degradation of D53, thereby triggering signal transduction and inhibiting tillering. A recent study discovered that nitrogen limitation induces SL biosynthesis in rice to activate the receptor D14, triggering SL signal transduction. Concurrently, nitrogen limitation also induces phosphorylation of the N-terminal disordered region (NTD) of D14, reducing the ubiquitination and degradation of receptor D14, thereby further enhancing SL perception. Through these two synergistic mechanisms, nitrogen limitation stimulates SL signal transduction, strongly inhibiting tillering and enabling rice to adapt to low nitrogen stress conditions. The study also found that the D14-D3 interaction induced by SL promotes the ubiquitination and degradation of D14, thereby mediating the termination of SL signal perception. These significant findings elucidate the mechanisms of activation and termination of SL perception in rice, revealing the crucial regulatory role of SL signals in controlling rice tillering under low nitrogen stress. This would provide key insights into plant adaptation to nutrient scarcity and guide the precise improvement of crop architecture and molecular breeding of rice for reduced fertilizer use and increased yield.

Climate change-induced global average temperature rise poses a severe threat to food production, in which maize, one of the three major global staple crops, is particularly susceptible to high temperatures. High temperatures significantly impact maize at various stages of its growth and development, especially during the reproductive growth stage, which can drastically reduce maize yields. Here we summarize the effects of high temperatures on maize at different growth stages, including germination, seedling, late vegetative growth, flowering, and grain-filling stages. We also review the main molecular mechanisms by which maize responds to heat stress, including heat shock and unfolded protein responses. Furthermore, we summarize the latest advances in heat-tolerant maize breeding in China. A batch of heat-tolerant hybrids and inbred lines have been identified through artificial high-temperature treatments and open field trials under natural high-temperature. In addition, we proposed important future research strategies in developing heat-tolerance maize, including new technological methods such as phenomics, genome-wide association studies, and genomic selection-based breeding, combined with intelligent agricultural management measures. We aim to cultivate maize varieties with high heat tolerance to cope with the high-temperature challenges brought about by climate change, thereby ensuring global food security.

Maize (Zea mays) is a staple crop worldwide, serving as a major source for food, feedstock, and industrial materials. Flowering time, a key agronomic trait determining diverse environmental adaptation and yield potential of crops, is determined by two developmental transitions (namely vegetative phase change and floral transition), and complicatedly regulated by internal factors (such as genetic factors and plant hormones) and external environmental factors. Given the importance of flowering time, in this review, we summarize the research progresses on the regulation of the two-phase transitions in maize, mainly focusing on the aspects of structural basis, physiological basis, genetic basis and molecular mechanisms. We also highlight the contribution of key flowering regulators to geographical adaptation of maize, and discuss future research directions on flowering and application in breeding, aiming to deepen our understanding of the genetic regulation of maize flowering and provide a theoretical basis for genetic improvement of maize cultivars adapting to diverse environmental conditions.

Multi-environment field testing is an important way to select optimize maize yield and yield stability varieties. However, because of its high cost, it has gradually become a challenge in plant breeding. The combination of field sparse testing and genome-wide prediction method can be used to predict untested phenotypes, reduced the effort and cost on field testing. In this experiment, 244 inbred lines of natural populations were planted in Shunyi, Beijing and Mishan, Heilongjiang in 2022 and 2023. Six agronomic traits were studied, including days to anthesis, plant height, ear height, ear length, kernel number per row and ear row number. The effects of four different models (Single, Across, M×E and R-norm), two different cross-validation schemes (CV1 and CV2) and three different training sets sampling ratios (0.5, 0.7 and 0.9) on the prediction accuracy were compared. The results showed that the average prediction accuracy of the six agronomic traits was 0.67, 0.58, 0.50, 0.33, 0.33 and 0.48. The average prediction accuracy of the Single model, Across model, M×E model and R-norm model was 0.36, 0.52, 0.53 and 0.53 for each trait. In CV1, the average prediction accuracy of each model in six traits ranged from 0.19 to 0.65, and in CV2, the average prediction accuracy ranged from 0.47 to 0.89. The comparison of different training set sampling ratios shows that the improvement of the proportion of the training sets has limited improvement in the prediction accuracy of different traits in different models, and the maximum is only 0.05. The results show that the CV2 training set can be used to form a scheme and include phenotypic data from multiple environments in the prediction model to provide good prediction accuracy for multi-environment prediction.

As one of the dual wings of innovative development, science popularization is a crucial means of enhancing national scientific literacy. Universities, as the main platforms for disseminating knowledge and nurturing talent, also bear the social responsibility of promoting science popularization. In biology, conducting science education and guiding students to extract biological knowledge from their courses to create popular science content is of great significance in advancing public science literacy. This article takes a university botany course as an example to illustrate how botany courses can integrate popular science education through course knowledge, practical activities, research outcomes, and real-life applications. By employing the “2W1H” approach (What, Why, and How), the paper guides students in creating popular science. This not only cultivates students’ comprehensive and innovative abilities but also disseminates biological knowledge, offering a valuable reference for the cultivation of popular science talents in the context of promoting science literacy for all.

Gene editing technology has become an important tool in crop breeding. Maize, one of the globally most important food crops, has been shown with great potential in the use of gene editing technology in genome research and breeding. In this paper, we reviewed the recent progress and applications of gene editing technology in maize research, with a focus on the latest achievements in maize genome editing by CRISPR/Cas. Firstly, we introduced the basic principles and types of gene editing technology, particularly the working mechanism of the CRISPR/Cas systems, and its application advantages in maize. Secondly, we summarized the research progress of gene editing technology in maize breeding, from basic genome editing to the editing of complex multi-gene regulation, aiming at the improvement of key traits such as yield, grain quality, and stress resistance. Finally, the outstanding research work in maize gene editing in China is presented and the existing issues of gene editing technology in maize breeding are discussed, along with an outlook on future development trends.

Mitochondria and chloroplasts are semi-autonomous organelles harboring their own genomes. RNA editing is essential for the correct expression of organelle genes. The mostly identified RNA editing is cytidine (C)-to-uridine (U). Multiple editing factors have been reported to be involved in RNA C→U editing. The PPR-motifs array in PPR proteins specifically target editing sites, and the DYW domains in PPR-DYW proteins catalyze the deaminase in the C→U editing. This paper aims to review the recent advance of PPR proteins involved in RNA C→U editing, and to discuss the potential application value of synthetic PPR editing factors.

Long non-coding RNAs (lncRNAs) are widely present in the genomes of eukaryotic organisms and play crucial roles in maintaining the biological activities of living organisms. In recent years, a large number of lncRNAs have been discovered in plants through high-throughput sequencing and bioinformatics analysis. LncRNAs play important roles in regulating plant growth, development, and stress responses. Due to the complexity of the genome and the low efficient of genetic transformation, the functional analysis of lncRNA in maize is relatively lagging behind comparing with that in Arabidopsis and rice. Maize is a major staple crop in China, playing a critical role in ensuring national food security. It’s also an important model plant in the fields of genetics and genomics. Understanding the research progress of lncRNA in maize is highly beneficial for comprehending the biological functions of lncRNA. Mining and analyzing the molecular regulatory network of lncRNAs involved in maize development and stress response can provide potential molecular targets for future genetic improvement of maize. In this review, we summarized the sources, classification, and action mechanisms of lncRNAs, and reviewed the discovery of lncRNAs in maize and their biological functions in regulating growth, development, and stress responses. We also discussed the current research status and provided an outlook on future researches of lncRNAs in maize.

Maize (Zea mays) is the main crop in China, and drought is a primary abiotic stress during its growth, resulting in direct reduction in grain yield and quality, thereby posing a threat to food security within the global climate context. At present, global climate change leads to extreme weather events, which aggravates the adverse effects on yield. Therefore, it is imperative to identify drought-resistant germplasm resources, elucidate the molecular mechanisms of drought stress response, and breed drought-resistant varieties. Here, we review recent advances in the genetic dissection of drought resistance in maize using methods such as genome-wide association study, quantitative trait locus gene cloning and multi-omics analysis. Additionally, we introduce potential strategies for genetic improvement of drought resistance by leveraging the identified genetic resources while discussing future perspectives within this research area.

Cytoplasmic male sterility (CMS) is a maternal genetic trait widely found in higher plants. CMS is not only a favorable material for studying the interaction between cytoplasmic and nuclear genomes, but also a crucial foundation for plant heterosis utilization. Maize is one of the most successful example for the utilization of heterosis in crops, and CMS has become a powerful tool for hybrid production to utilize heterosis in maize. Therefore, the molecular mechanism of CMS in maize has always been a research hotspot. In this paper, CMS related genes and fertility restorer genes discovered in the three major types of CMS in maize were summarized, and the problems that needed to be solved in CMS-related research and development prospects in the application of CMS in maize were discussed. This review provided theoretical reference for better understanding of the molecular mechanism of CMS in plant and the application of CMS system for hybrid seed production in the utilization of heterosis in maize.

Maize (Zea mays) is the major grain crop with the largest planting area and the highest total yield in China, and it is also a model of heterosis utilization. However, compared with developed countries, China is still facing several outstanding problems in maize production, such as low average yield, lack of breakthrough varieties and high cost of hybrid seed production. The main solution to these problems is the application of male-sterile lines with better heterosis utilization efficiency and thus increase the yield per unit area of maize. In this review, we summarize the latest advances of male sterility research in maize, including its classification, gene cloning and functional analysis, molecular regulatory network construction, and discuss the strategies of creating novel male-sterility systems and their potential/future application in maize breeding. This review provides guidelines for the male-sterility based/assisted hybrid breeding and seed production in maize.

Plants encounter various abiotic stresses throughout their lifecycle, including heat, drought, and salt stress, all of which have diverse impacts on their growth and development. Global warming has exacerbated the impact of heat stress on crops such as maize, potentially leading to growth retardation and reduced reproductive capacity. As an important staple crop, the yield and quality of maize are severely compromised by heat stress. Plants respond to heat stress through complex molecular mechanisms involving multiple signal transduction pathways and the regulation of gene expression. It is crucial to use advanced techniques such as genetics, genomics, multi-omics analysis, and high-throughput phenotyping to extensively explore and analyze the genes and loci associated to abiotic stress tolerance, including heat stress, in the maize genome. These studies not only deepen our understanding of the biological mechanisms underlying maize stress tolerance but also provide valuable molecular markers and candidate gene resources for breeders to accelerate the development of new maize varieties.

Leaf, as a photosynthetic organ of crops, its senescence process has an important impact on yield formation, but the relationship between leaf senescence and phyllosphere microorganisms has been less studied. In order to explore the impact of the senescence process of maize leaves on the phyllosphere bacterial community, this study used three maize varieties of different maturity time (early-maturation variety Heike Yu 17 (H17), mid-maturation variety Zhongdan 111 (Z111), and late-maturation variety Shen Yu 21 (S21) in Northeast China as the experimental materials, and the leaves of the ear position of the three maize varieties were sampled five times starting from the blooming stage of early- maturation varieties, and the physiological indexes of senescence were determined. And at the same time, the community composition of endogenous and exogenous bacteria in/on the leaves was determined based on high-throughput sequencing technology. The results showed that at the late reproductive stage, leaf water content, POD and SOD activities were significantly higher in the mid- and late-maturation varieties than in the early-maturation varieties. At the phylum level, Cyanobacteria were endemic to mid- and late-maturation cultivars; at the genus level, the relative abundance of the endogenous shared bacteria Sphingomonas, Methylobacterium, and Deinococcus in maize leaves decreased significantly at later stages of maturation (IV and V). The relative abundance of endogenous bacteria Streptomyces and exogenous bacteria P3OB-42 were significantly enriched in the late senescence period, with similar trends and significant differences in relative abundance among the three species. The relative abundance of endogenous and exogenous bacteria differed significantly, with the top 5 exogenous bacteria accounting for more than 60%, while for endogenous bacteria, the top 5 accounted for only more than 30%. Soluble sugar content, photosynthetic pigment content and SOD activity were significantly correlated with bacterial community structure and abundance. In conclusion, mid- and late-maturation varieties were effective in prolonging leaf greening period, maintaining late leaf physiological activity with delaying senescence. The effects of senescence on the composition and diversity of endogenous bacterial communities were significantly greater than those of exogenous bacteria, and there were significantly different genera among three maize varieties studied. Moreover, soluble sugar content, photosynthetic pigment content and SOD activity were the key factors affecting the phyllosphere bacterial communities as well as the dominant species.