Late embryogenesis-abundant (LEA) genes play important roles in plant growth and development, especially the cellular dehydration tolerance during seed maturation. In order to comprehensively understand the roles of LEA family members in wheat, we carried out a series of analyses based on the latest genome sequence of the bread wheat Chinese Spring. 121 Triticum aestivum L. LEA (TaLEA) genes, classified as 8 groups, were identified and characterized. TaLEA genes are distributed in all chromosomes, most of them with a low number of introns (≤3). Expression profiles showed that most TaLEA genes expressed specifically in grains. By qRT-PCR analysis, we confirmed that 12 genes among them showed high expression levels during late stage grain maturation in two spring wheat cultivars, Yangmai16 and Yangmai15. For most genes, the peak of expression appeared earlier in Yangmai16. Statistical analysis indicated that expression level of 8 genes in Yangmai 16 were significantly higher than Yangmai 15 at 25 days after anthesis. Taken together, our results provide more knowledge for future functional analysis and potential utilization of TaLEA genes in wheat breeding.

Stomata are microscopic pores on the plant epidermis that serve as a major passage for the gas and water exchange between a plant and the atmosphere. The formation of stomata requires a series of cell division and cell-fate transitions and some key regulators including transcription factors and peptides. Monocots have different stomatal patterning and a specific subsidiary cell formation process compared with dicots. Cell-to-cell symplastic trafficking mediated by plasmodesmata (PD) allows molecules including proteins, RNAs and hormones to function in neighboring cells by moving through the channels. During stomatal developmental process, the intercellular communication between stomata complex and adjacent epidermal cells are finely controlled at different stages. Thus, the stomata cells are isolated or connected with others to facilitate their formation or movement. In the review, we summarize the main regulation mechanism underlying stomata development in both dicots and monocots and especially the specific regulation of subsidiary cell formation in monocots. We aim to highlight the important role of symplastic connection modulation during stomata development, including the status of PD presence at different cell–cell interfaces and the function of relevant mobile factors in both dicots and monocots.

Climate change and cropping-system adjustments have caused widespread delayed sowing, limiting wheat growth and yield. Although optimized nitrogen management can partially mitigate late-sowing stress, the optimal nitrogen rate and basal–topdressing ratio for late-sown high-quality wheat remain undefined, limiting the development of targeted cultivation strategies. To solve the above scientific problems and clarify the regulatory effects of nitrogen fertilizer application regimes on the yield and quality of late-sown wheat, a two-year fixed-field experiment was carried out in this study. The late-sowing-tolerant wheat cultivar Yangmai 25 was used as the material. With a sowing date of 25 November (delayed by 20 days compared to the optimal sowing period), a split-plot field experiment was carried out with two factors: nitrogen application rate (225 and 300 kg N·ha⁻¹) assigned to the main plots, and basal–topdressing ratio among the basal-, tillering-, and jointing-stage fertilizer applications (7:1:2, 5:1:4, and 3:3:4) arranged in the sub-plots. The results showed that both the nitrogen application rate and basal–topdressing ratio comparison had highly significant effects on the grain yield of Yangmai 25. Under the same basal–topdressing ratio, increasing the nitrogen application rate from 225 to 300 kg·ha⁻¹ improved the spike number and grains per spike, but reduced the 1000-grain weight and grain yield. Under the same nitrogen application rate, increasing the topdressing proportion improved the grain number per spike, 1000-grain weight, and yield, while the spike number decreased. Specifically, the 3:3:4 management strategy resulted in an average yield increase of 3.11% and 8.94% over two years compared to the 5:1:4 and 7:1:2 strategies, respectively. Both the nitrogen application rate and basal–topdressing ratio had highly significant effects on quality indicators, such as protein content, wet gluten content, sedimentation value, dough formation time, sodium carbonate solvent retention capacity (SRC), sucrose SRC, and other quality indicators, but had minimal impact on grain hardness, water absorption, and water SRC. Under the same nitrogen application rate, the basal–topdressing ratio of 3:3:4 significantly increased grain protein content, wet gluten content, sedimentation value, dough development time, and dough stability time compared to the 7:1:2 treatment. In addition, under the experimental conditions of this study, the 225 kg·ha⁻¹ nitrogen application rate combined with the 3:3:4 basal–topdressing ratio achieved better comprehensive performance in the yield and quality of Yangmai 25 compared with that of the 300 kg·ha⁻¹ treatment. Further experiments are required to determine the optimal nitrogen application rate for this cultivar under late-sowing conditions.