Identifying changes in the wheat kernel proteome under heat stress using iTRAQ

Wheat(Triticum aestivum L.) is one of the three major global food crops. Hightemperature stress can affect its yield and quality. Studies of the effect of hightemperature stress on wheat kernel development are important because they can reveal the stability of wheat quality and lead to the genetic improvement of wheat quality traits. In this study, the isobaric tags for relative and absolute quantitation(iTRAQ)method was adopted to analyze changes in the protein expression profile of wheat cultivars under high temperature stress. The protein content of wheat grain increased under heat stress, while the SDS-sedimentation value and starch content decreased.Grain filling was deficient under high temperature stress, which reduced thousandkernel weight but did not affect wheat kernel length. The 207 differentially expressed proteins identified in Gaocheng 8901 under heat stress were associated with energy metabolism, growth and development, and stress response. Gene Ontology enrichment analysis showed that the annotated proteins that were differentially expressed in Gaocheng 8901 under heat stress were involved mainly in stimulus response, abiotic stress response, stress response, and plasma membrane. A set of 78 differentially expressed proteins were assigned to 83 KEGG signaling/metabolic pathways. KEGG pathway enrichment analysis showed that this set of proteins was significantly enriched in members of 51 pathways, and the proteins participated mainly in protein synthesis in the endoplasmic reticulum, starch and sucrose metabolism, and reaction on ribosomes. Five differentially expressed proteins were involved in protein–protein interaction networks that may greatly influence the yield and quality of wheat grain. In wheat, high-temperature stress leads to a variety of effects on protein expression and may ultimately cause changes in yield and quality.

TaMADS29 interacts with TaNF-YB1 to synergistically regulate early grain development in bread wheat

Grain development is a crucial determinant of yield and quality in bread wheat(Triticum aestivum L.).However,the regulatory mechanisms underlying wheat grain development remain elusive.Here we report how Ta MADS29 interacts with Ta NF-YB1 to synergistically regulate early grain development in bread wheat.The tamads29 mutants generated by CRISPR/Cas9 exhibited severe grain filling deficiency,coupled with excessive accumulation of reactive oxygen species(ROS)and abnormal programmed cell death that occurred in early developing grains,while overexpression of Ta MADS29 increased grain width and1,000-kernel weight.Further analysis revealed that Ta MADS29 interacted directly with Ta NF-YB1;null mutation in Ta NF-YB1caused grain developmental deficiency similar to tamads29 mutants.The regulatory complex composed of Ta MADS29 and Ta NF-YB1 exercises its possible function that inhibits the excessive accumulation of ROS by regulating the genes involved in chloroplast development and photosynthesis in early developing wheat grains and prevents nucellar projection degradation and endosperm cell death,facilitating transportation of nutrients into the endosperm and wholly filling of developing grains.Collectively,our work not only discloses the molecular mechanism of MADS-box and NF-Y TFs in facilitating bread wheat grain development,but also indicates that caryopsis chloroplast might be a central regulator of grain development rather than merely a photosynthesis organelle.More importantly,our work offers an innovative way to breed high-yield wheat cultivars by controlling the ROS level in developing grains.

TaANR1-TaMADS25 module regulates lignin biosynthesis and root development in wheat(Triticum aestivum L.)

Common wheat is a staple food for 35%of the global population,therefore increasing wheat yield in an ever-changing environment is essential for food security in the present day(Peng et al.,2011).Root system is responsible for water and nutrient acquisition,thus crucial for competitive fitness and crop yield in challenging environments(Karlova et al.,2021;Liu et al.,2022).Over the past decades,extensive research has focused on identifying genes accountable for root growth and development in plants(Rogers and Benfey,2015).However,only a limited number of genes have been cloned in wheat(Li et al.,2021).

Transcriptome analysis of wheat grain using RNA-Seq

With the increase in consumer demand,wheat grain quality improvement has become a focus in China and worldwide.Transcriptome analysis is a powerful approach to research grain traits and elucidate their genetic regulation.In this study,two cDNA libraries from the developing grain and leaf-stem components of bread wheat cultivar,Nongda211,were sequenced using Roche/454 technology.There were 1061274 and 1516564 clean reads generated from grain and leaf-stem,respectively.A total of 61393 high-quality unigenes were obtained with an average length of 1456 bp after de novo assembly.The analysis of the 61393 unigenes involved in the biological processes of the grain showed that there were 7355 differentially expressed genes upregulated in the grain library.Gene ontology enrichment and the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that many transcription products and transcription factors associated with carbohydrate and protein metabolism were abundantly expressed in the grain.These results contribute to excavate genes associated with wheat quality and further study how they interact.