RUS6, a DUF647-containing protein, is essential for early embryonic development in Arabidopsis thaliana

Abstract

Background The Arabidopsis RUS (ROOT UV-B SENSITIVE) gene family contains six members, each of which encodes a protein containing a DUF647 (domain of unknown function 647) that is commonly found in eukaryotes. Previous studies have demonstrated that RUS1 and RUS2 play critical roles in early seedling development. All six RUS genes are expressed throughout the plant, but little is known about the functional roles of RUS3, RUS4, RUS5 and RUS6. Results We used a reverse-genetic approach to identify knockout mutants for RUS3, RUS4, RUS5 and RUS6. Each mutant was confirmed by direct DNA sequencing and genetic segregation analysis. No visible phenotypic differences were observed in rus3, rus4, or rus5 knockout mutants under standard growth conditions, but rus6 knockout mutants displayed a strong embryo-lethal phenotype. Two independent knockout lines for RUS6 were characterized. The rus6 mutations could only be maintained through a heterozygote, because rus6 homozygous mutants did not survive. Closer examinations of homozygous rus6 embryos from rus6/ + parent plants revealed that RUS6 is required for early embryo development. Loss of RUS6 resulted in embryo lethality, specifically at the mid-globular stage. The embryo-lethality phenotype was complemented by a RUS6::RUS6-GFP transgene, and GFP signal was detected throughout the embryo. Histological analyses with the β-glucuronidase reporter gene driven by the RUS6 promoter showed tissue- and development-specific expression of RUS6, which was highest in floral tissues. Conclusion Our data revealed that RUS6 is essential for early embryo development in Arabidopsis, and that the RUS gene family functions in multiple stages of plant development.

Weighted Gene Correlation Network Analysis (WGCNA) of Arabidopsis Somatic Embryogenesis (SE) and Identification of Key Gene Modules to Uncover SE-Associated Hub Genes

“…In addition, ROOT UV-B SENSITIVE 6 ( RUS6 ; AT5G49820), which encodes a DUF647 (DOMAIN OF UNKNOWN FUNCTION 647) containing protein, an ankyrin repeat-containing gene designated as AT5G65860 and a gene that encodes hydroxyproline- O -glycosyltransferases (Hyp- O -GALT), GALT4 ( AT1G27120 )), was also identified as hub genes in the coexpression network. The members of the RUS gene family play diverse roles in plant development [ 66 ]. Interestingly, knockout mutants of RUS6 have shown a strong embryo-lethal phenotype.…”

Identification of Low Temperature Inducible Genes of Lactuca sativa by Using Suppression Subtractive Hybridization Method

“…There are very few regarding the functions of RUS proteins. Recently, Rus5 knockout mutant of Arabidopsis was reported to show no visible phenotypic difference to wild type under normal growth conditions (Perry et al, 2021). At present, function of lettuce RUS5 is also not estimated under low temperature.…”

Transcriptomic analysis of OsRUS1 overexpression rice lines with rapid and dynamic leaf rolling morphology

“…AtRUS1 / WXR3 ( WEAK AUXIN RESPONSE 3 ) and AtRUS2 / WXR1 have functions involved in very-low fluence (VLF) UVB responses and vitamin B6 (VB6) homeostasis 17 – 19 , or regulation of polar auxin transport 20 , 21 . Recently, Arabidopsis RUS4 was reported to play a role in male fertility 22 , and RUS6 in early embryo development 23 . However, no leaf rolling phenotype of AtRUS / WXR genes has been reported in Arabidopsis .…”