[NAC transcription factors family and increased tolerance to water deficiency in plants]. / Rodzina czynników transkrypcyjnych NAC a zwiekszenie tolerancji na stres niedoboru wody u roslin.

Transcription factors are proteins that are able to regulate the expression of target genes by specifically binding with DNA sequences and regulating the activity initiation complex of transcription. These proteins are key elements in the adaptation of plants to environmental conditions. Families of transcription factors that are associated with a response to stress are DREB/CBF, AREB/ABF, MYB/MYC and NAC. The NAC gene family is one of the largest families of transcription factors. Members of the NAC family have been identified in many plant species. NAC TFs are involved in the growth, development and response of plants to biotic and abiotic stress. Many transcription factors belonging to the NAC family, including SNAC1, are involved in the response of plants to water deficiency. Drought is the most harmful environmental stress in worldwide agriculture. Obtaining plants with an increased tolerance to water deficiency by using the methods of molecular biology has become a major goal of plant breeding.

HorTILLUS-A Rich and Renewable Source of Induced Mutations for Forward/Reverse Genetics and Pre-breeding Programs in Barley (Hordeum vulgare L.).

TILLING (Targeting Induced Local Lesions IN Genomes) is a strategy used for functional analysis of genes that combines the classical mutagenesis and a rapid, high-throughput identification of mutations within a gene of interest. TILLING has been initially developed as a discovery platform for functional genomics, but soon it has become a valuable tool in development of desired alleles for crop breeding, alternative to transgenic approach. Here we present the HorTILLUS ( Hordeum-TILLING-University of Silesia) population created for spring barley cultivar "Sebastian" after double-treatment of seeds with two chemical mutagens: sodium azide (NaN3) and N-methyl-N-nitrosourea (MNU). The population comprises more than 9,600 M2 plants from which DNA was isolated, seeds harvested, vacuum-packed, and deposited in seed bank. M3 progeny of 3,481 M2 individuals was grown in the field and phenotyped. The screening for mutations was performed for 32 genes related to different aspects of plant growth and development. For each gene fragment, 3,072-6,912 M2 plants were used for mutation identification using LI-COR sequencer. In total, 382 mutations were found in 182.2 Mb screened. The average mutation density in the HorTILLUS, estimated as 1 mutation per 477 kb, is among the highest mutation densities reported for barley. The majority of mutations were G/C to A/T transitions, however about 8% transversions were also detected. Sixty-one percent of mutations found in coding regions were missense, 37.5% silent and 1.1% nonsense. In each gene, the missense mutations with a potential effect on protein function were identified. The HorTILLUS platform is the largest of the TILLING populations reported for barley and best characterized. The population proved to be a useful tool, both in functional genomic studies and in forward selection of barley mutants with required phenotypic changes. We are constantly renewing the HorTILLUS population, which makes it a permanent source of new mutations. We offer the usage of this valuable resource to the interested barley researchers on cooperative basis.