Search Results (3)

Background: Ethylene is one of the most important plant hormones. ACC oxidase (ACO) plays a vital role in ethylene synthesis and responses to biotic and abiotic stresses in plants. However, its function in Triticum urartu remains unclear. This study aims to systematically identify the members of the TuACO gene family to elucidate its response characteristics and functions under biotic and abiotic stresses. Methods: Through homologous alignment, phylogenetic evolution analysis, and investigations of gene structure and promoter cis-elements, a total of eight TuACO genes were identified in the T. urartu genome based on their homology to OsACO and AtACO protein sequences. Results: These genes were classified into five ACO subfamilies and distributed across chromosomes 1A, 4A, 5A, 6A, and 7A. TuACO gene families contained 0–3 introns and 1–4 exons. The protein sequence contains 10 different conservative motifs. QRT-PCR expression analysis revealed that the transcript levels of TuACO5a, TuACO5b, and TuACO3a were significantly upregulated at 6 and 24 h after infection with powdery mildew, a biotic stress. Under boron deficiency, an abiotic stress, the expression of TuACO6 and TuACO1b increased, whereas the expression of TuACO5b and TuACO3b was markedly induced under high-boron conditions. Conclusions: These results demonstrate that TuACO genes exhibit functional diversification in response to biotic and abiotic stresses, which lays the foundation for elucidating their gene functions. Full article

Black amaranth (Amarantus quitensis Kunth) is an ancestral crop of the Ecuadorian Andean region, where traditionally it is called ataco or sangorache. Nowadays, there is some information about the phenotypic diversity of black amaranth landraces, but there are no data about their genetic diversity. In this study, we evaluated the genetic diversity of 139 black amaranth accessions collected twice (1981–1986 and 2014–2015) in three representative Ecuadorian Andean provinces for this crop (Imbabura, Tungurahua, and Cañar) using nine simple sequence repeats (SSR) markers. We detected low genetic diversity levels; only a total of 36 alleles were amplified in 139 accessions, with a mean allelic richness of 4.0 per marker, observed heterozygosity of 0.014, expected heterozygosity of 0.134, and Shannon’s information index of 0.297. In addition, only 17 genotypes were found, with a predominant genotype (83.6%) and up to 12 accession-unique genotypes. Moreover, a certain genetic diversity decrease was observed over the last decades, especially in Tungurahua and Cañar, where today practically only the predominant genotype exists. The ataco germplasm is genetically structured into two well-defined genotype clusters and could constitute two different genetic lineages. Furthermore, a clear association of each genotype group with a different color morphotype defined in a previous agromorphological characterization was observed. The accessions of the majority group of genotypes showed purple pigmentation in stems, leaves, and inflorescences, whereas those of the other genotype group showed less intense pigmentation (pink stems, inflorescences, and green leaves). Molecular information obtained in this study may be useful for the suitable management and conservation of this underutilized genetic plant resource that is of great food and cultural significance for indigenous farming communities of the Ecuadorian highlands. Full article

Waterlogging stress significantly affects the growth, development, and productivity of crop plants. However, manipulation of gene expression to enhance waterlogging tolerance is very limited. In this study, we identified an ethylene-responsive factor from barley, which was strongly induced by waterlogging stress. This transcription factor named HvERF2.11 was 1158 bp in length and encoded 385 amino acids, and mainly expressed in the adventitious root and seminal root. Overexpression of HvERF2.11 in Arabidopsis led to enhanced tolerance to waterlogging stress. Further analysis of the transgenic plants showed that the expression of AtSOD1, AtPOD1 and AtACO1 increased rapidly, while the same genes did not do so in non-transgenic plants, under waterlogging stress. Activities of antioxidant enzymes and alcohol dehydrogenase (ADH) were also significantly higher in the transgenic plants than in the non-transgenic plants under waterlogging stress. Therefore, these results indicate that HvERF2.11 plays a positive regulatory role in plant waterlogging tolerance through regulation of waterlogging-related genes, improving antioxidant and ADH enzymes activities. Full article