OsSFR6 is a functional rice orthologue of SENSITIVE TO FREEZING‐6 and can act as a regulator of COR gene expression, osmotic stress and freezing tolerance in Arabidopsis

Abstract

Summary• The Arabidopsis protein SENSITIVE TO FREEZING-6 (AtSFR6) is required for cold-and drought-inducible expression of COLD-ON REGULATED (COR) genes and, as a consequence, AtSFR6 is essential for osmotic stress and freezing tolerance in Arabidopsis. Therefore, orthologues of AtSFR6 in crop species represent important candidate targets for future manipulation of stress tolerance. We identified and cloned a homologue of AtSFR6 from rice (Oryza sativa), OsSFR6, and confirmed its orthology in Arabidopsis.• OsSFR6 was identified by homology searches, and a full-length coding region isolated using reverse transcription polymerase chain reaction (RT-PCR) from Oryza sativa cDNA. To test for orthology, OsSFR6 was expressed in an Arabidopsis sfr6 loss-of-function mutant background, and restoration of wild-type phenotypes was assessed.• Searching the rice genome revealed a single homologue of AtSFR6. Cloning and sequencing the OsSFR6 coding region showed OsSFR6 to have 61.7% identity and 71.1% similarity to AtSFR6 at the predicted protein sequence level. Expression of OsSFR6 in the atsfr6 mutant background restored the wild-type visible phenotype, as well as restoring wild-type levels of COR gene expression and tolerance of osmotic and freezing stresses.• OsSFR6 is an orthologue of AtSFR6, and thus a target for future manipulation to improve tolerance to osmotic and other abiotic stresses.

The Arabidopsis Mediator Complex Subunits MED16, MED14, and MED2 Regulate Mediator and RNA Polymerase II Recruitment to CBF-Responsive Cold-Regulated Genes

“…All transcripts studied were detected using validated gene-specific primers (Supplemental Table 3) using Go-Taq quantitative PCR mastermix with SYBR green and ROX (Promega). Expression levels were normalized to the expression of PEX4 (At5g25760) (Wathugala et al, 2011). For each cDNA sample tested, three technical replicate reactions with gene specific primers and three technical replicate reactions with PEX4-specific primers were performed in a 96-well optical plate.…”

SFR6 Protein of freezing tolerance in Arabidopsis does not affect localization of CBF1 protein

“…Overexpression of AtSFR6 in sfr6-1 mutant background complemented all visible phenotypes of sfr6-1 mutant (Wathugala et al, 2011). However, overexpression of AtSFR6 in wild type Arabidopsis did not alter downstream cold gene expression (Wathugala et al, 2011). Further, over-expression of CBF genes in the sfr6-1 mutant did not alter COR gene expression (Knight et al, 2009).…”

“…AtSFR6 has been identified as At4g04929 protein (Knight et al, 2009) a plant mediator sub-unit (Backstrom et al, 2007). Overexpression of AtSFR6 in sfr6-1 mutant background complemented all visible phenotypes of sfr6-1 mutant (Wathugala et al, 2011). However, overexpression of AtSFR6 in wild type Arabidopsis did not alter downstream cold gene expression (Wathugala et al, 2011).…”

“…SFR6 was identified as a 135kDa protein (Knight et al, 2009) of subunit MED16 of plant mediator complex (Backstrom et al, 2007). Further the over expression of AtSFR6 did not increase KIN2 (downstream gene of CBF pathway) expression in wild type Arabidopsis either under ambient temperatures (Wathugala et al, 2011) or after cold exposure (Wathugala et al, 2012). Thus it is possible that SFR6 controls localization of CBF proteins in Arabidopsis.…”

Análisis genético de la percepción del ácido salicílico en Arabidopsis thaliana. Caracterización de NRB4

“…El ortólogo de MED25/PFT1 en Triticum aestivum (trigo), TaPFT1, puede complementar los fenotipos de patogenicidad y floración del mutante pft1 de Arabidopsis (Kidd et al 2009). El ortólogo de MED16/SFR6 (STRUBBELIG-RECEPTOR FAMILY 6) en arroz, OsSFR6, puede restaurar los fenotipos de falta de tolerancia a estrés osmótico y al frío presentes en el mutante sfr6 de Arabidopsis (Wathugala et al 2011). objetivos objetivos objetivos objetivos objetivos objetivos objetivos objetivos…”