The TIFY family, a plant-specific group of transcription factors, plays critical roles in regulating growth, development, and stress responses. This study aimed to clone TaTIFY11c-4A in wheat, validate its genetic effects, and provide a theoretical basis for high-yield molecular breeding of wheat.

The wheat cultivar Hanxuan 10 was used to clone TaTIFY11c-4A and allelic variations were detected in germplasms. The tissue-specific expression patterns of TaTIFY11c-4A and its responses to various hormones and stresses were analyzed via quantitative real-time PCR (qRT-PCR). The subcellular localization of TaTIFY11c-4A was determined through transient expression in tobacco. A molecular marker targeting the polymorphic site in TaTIFY11c-4A was developed to assess the genotypes in the natural population, and association analysis was performed to evaluate the correlations between the genotypes and phenotypes. Additionally, the spatial and temporal distribution of different genotypes were analyzed. Synergistic effects of TaTIFY11c-4A and TaSRL1-4A haplotypes were explored to identify superior genotype.

TaTIFY11c-4A was successfully cloned, comprising three exons and two introns, encoding a 198-amino acid protein with conserved TIFY and Jas domains. TaTIFY11c-4A is expressed in roots, root bases and leaves at the seedling stage, and highly expressed in roots and leaves at the booting stage. There are multiple cis-acting elements related to hormone responses, stress adaptation, and endosperm development in the promoter of TaTIFY11c-4A. Its expression responds to plant hormones (ABA, IAA, MeJA) and abiotic stresses (drought, high salinity, low and high temperature). A SNP (G/A) was identified in its promoter at -405 bp. A molecular marker was developed based on the SNP and association analysis revealed significant correlations between TaTIFY11c-4A alleles and plant height, thousand grain weight under multiple environments such as drought and high temperature, and root depth at tillering stage. Compared with genotype SNP-G, wheat germplasms carrying the SNP-A allele exhibited shorter plants, higher thousand grain weight, and shallower roots at tillering stage, and have been positively selected in the wheat breeding process. TaTIFY11c-4A-SNP-A and TaSRL1-4A-SNP-C genotypes synergistically reduced plant height and enhanced thousand grain weight.

TaTIFY11c-4A encodes a nuclear-localized JAZ protein. It is expressed in various tissues of wheat and involved in responses to ABA, IAA, MeJA, as well as abiotic stresses such as drought, extreme temperature, and high salinity. The TaTIFY11c-4A-SNP is associated with plant height and thousand grain weight under multiple environments, and root depth. SNP-A allele has been positively selected in the wheat breeding process. The superior genotypes and combinations of TaTIFY11c-4A and TaSRL1-4A provide genetic resources for breeding high-yield and stress-resistant wheat cultivars.

To evaluate the drought resistance of synthetic wheat germplasm based on multi-source images collected by unmanned aerial vehicle (UAV) and yield data, explore high-throughput indices for drought resistance evaluation, and identify synthetic wheat germplasm resources with drought resistance. This provides technical support and germplasm materials for accelerating the expansion of drought-resistant genetic resources for wheat and enhancing the level of breeding for dryland wheat.

Eighty synthetic wheat germplasm and the control variety Xin Chun 37 were used as plant materials, which were sown in the field and treated with a water regime of drought stress and irrigation. Multi-source images of test materials during filling stage were collected by multi-spectral and thermal infrared cameras equipped with unmanned aerial vehicle, and the spectral index of each test material was extracted by threshold segmentation. The analyses of Pearson’s correlation and principal component were performed to identify drought resistance-related spectral indices, and the drought resistance of each synthetic wheat germplasm was determined by single index and comprehensive evaluation methods.

The drought resistance coefficients of 19 spectral indices of 80 synthetic wheat germplasm were calculated based on multisource imagery data obtained from unmanned aerial vehicles. The correlation analysis between the spectral indices and the yield-based drought index (DRI) showed that among the drought resistance coefficients of the 19 spectral indices, OSAVI exhibited the highest correlation with the drought index, while NDVI, CI_re, and NDRE demonstrated relatively strong associations with the drought index. However, the different drought indices showed a high correlation, resulting in redundant information. The drought resistance coefficients of the 19 spectral indices were transformed into three independent comprehensive indicators through principal component analysis, with contribution rates of 59.6%, 12.0% and 9.6%, respectively. The comprehensive drought resistance index (D) for each synthetic wheat germplasm were calculated by aggregating the three independent comprehensive indicators using the weighted membership function method. 6 and 5 synthetic wheat germplasms with strong drought resistance were identified based on DRI and D, respectively. Among them, 2 germplasms (SW004 and SW009) with high drought resistance were detected based on both DRI and D. Furthermore, the drought resistance of the 80 synthetic wheat germplasms was graded based on the drought resistance coefficient of OSAVI, and the grading results were found to be consistent with that based on the D value. Among the six strongly drought-resistant germplasms identified based on the drought resistance coefficient of OSAVI, five of them were also classified as strongly drought-resistant germplasms based on comprehensive drought resistance evaluation.

The spectral indices NDVI, OSAVI, CI_re and NDRE extracted from UAV-based multi-source images, as well as the drought resistance comprehensive evaluation value can be used to assist in the identification of drought resistance of wheat germplasm.

Enolase is a key rate-limiting enzyme in the process of glycolysis, and plays a crucial role in plant growth and development, and response to abiotic stress. The function of common wheat enolase gene TaENO1-5B was revealed and molecular markers were developed to provide genetic resources for improving wheat through molecular breeding.

TaENO1-5B was cloned from wheat variety Hanxuan 10. The domains of its encoded protein were analyzed on the SMART website. The secondary and tertiary structures of the protein were predicted by Phyre2 software. Real-time quantitative fluorescent PCR was used to analyze the expression levels of the target gene in wheat tissues at different developmental stages and its expression patterns under phytohormone treatment and abiotic stress. Thirty wheat germplasm with rich genetic diversity were used as plant materials to analyze the gene sequence polymorphisms, and develop molecular markers. The association analysis between TaENO1-5B haplotypes and phenotypic traits was carried out in a natural population consisting of 323 wheat accessions. The trend of breeding selection of superior haplotype in different wheat production zones in China was analyzed by using a landrace population and a modern variety population.

TaENO1-5B gene consists of 17 exons and 16 introns encoding 446 amino acids and contains a conserved N-terminal domain and a C-terminal TIM (triose-phosphate isomerase) barrel domain. TaENO1-5B was expressed in all tissues of wheat at seedling, jointing, heading and flowering stages, and the expression level was higher in roots, root bases and spikes. The TaENO1-5B promoter region contains a variety of cis-acting elements, including elements responding to plant hormones, such as abscisic acid (ABA), auxin (IAA), and methyl jasmonate (MeJA), as well as elements responding to drought and low temperature. The expression of TaENO1-5B was significantly induced by phytohormones and abiotic stress in wheat. Four SNPs were detected in the promoter region and three SNPs in the gene region of the TaENO1-5B gene, which constituted three haplotypes, i.e., Hap-5B-1, Hap-5B-2, and Hap-5B-3. Among them, Hap-5B-2 was a favorable haplotype highly associated with shorter plant height, more spikelets per spike, and more grains per spike under various environments such as drought and high temperature, and had been positively selected in the breeding history of major wheat production zones in China. The KASP (kompetitive allele-specific PCR) marker developed based on the SNP (2 399 bp, G/A) of the TaENO1-5B promoter region was significantly correlated with the spikelet number per spike in multiple environments.

TaENO1-5B gene responds to phytohormones and abiotic stress, and is significantly correlated with plant height, spikelet number per spike and grain number per spike under various environments such as drought and high temperature. Hap-5B-2 is a favorable haplotype with shorter plant height and more number of spikelets and grains per spike. Molecular markers developed based on the variation sites of TaENO1-5B gene sequence can be used for genetic improvement of plant height and related yield traits in wheat.