isolation-of-high-purity-tissues-from-developing-barley-seeds

Isolation of High Purity Tissues from Developing Barley Seeds

Understanding the mechanisms regulating the development of cereal seeds is essential for plant breeding and increasing yield. However, the analysis of ...

Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany

Chromosome organization, dynamics and stability are required for successful passage through cellular generations and transmission of genetic information to offspring. The key components involved are Structural maintenance of chromosomes (SMC) complexes. Cohesin complex ensures proper chromatid alignment, condensin complex chromosome condensation and the SMC5/6 complex is specialized in the maintenance of genome stability. Here we summarize recent knowledge on the composition and molecular functions of SMC5/6 complex. SMC5/6 complex was originally identified based on the sensitivity of its mutants to genotoxic stress but there is increasing number of studies demonstrating its roles in the control of DNA replication, sister chromatid resolution and genomic location-dependent promotion or suppression of homologous recombination. Some of these functions appear to be due to a very dynamic interaction with cohesin or other repair complexes. Studies in Arabidopsis indicate that, besides its canonical function in repair of damaged DNA, the SMC5/6 complex plays important roles in regulating plant development, abiotic stress responses, suppression of autoimmune responses and sexual reproduction.

Scaffolding for Repair: Understanding Molecular Functions of the SMC5/6 Complex.

The maintenance of genome integrity over cell divisions is critical for plant development and the correct transmission of genetic information to the progeny. A key factor involved in this process is the STRUCTURAL MAINTENANCE OF CHROMOSOME5 (SMC5) and SMC6 (SMC5/6) complex, related to the cohesin and condensin complexes that control sister chromatid alignment and chromosome condensation, respectively. Here, we characterize  () paralogs of the SMC5/6 complex in Arabidopsis (). NSE4A is expressed in meristems and accumulates during DNA damage repair. Partial loss-of-function  mutants are viable but hypersensitive to DNA damage induced by zebularine. In addition,  mutants produce abnormal seeds, with noncellularized endosperm and embryos that maximally develop to the heart or torpedo stage. This phenotype resembles the defects in cohesin and condensin mutants and suggests a role for all three SMC complexes in differentiation during seed development. By contrast,  is expressed in only a few cell types, and loss-of-function mutants do not have any obvious abnormal phenotype. In summary, our study shows that the NSE4A subunit of the SMC5-SMC6 complex is essential for DNA damage repair in somatic tissues and plays a role in plant reproduction.

Article	Year
Scaffolding for Repair: Understanding Molecular Functions of the SMC5/6 Complex. Genes\| PubMed ID: 29329249	2018
The SMC5/6 Complex Subunit NSE4A Is Involved in DNA Damage Repair and Seed Development. The Plant cell\| PubMed ID: 31036599	2019

Ales Pecinka

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