Generation of Transgenic Self-Incompatible Arabidopsis thaliana Shows a Genus-Specific Preference for Self-Incompatibility Genes

Abstract

Brassicaceae species employ both self-compatibility and self-incompatibility systems to regulate post-pollination events. Arabidopsis halleri is strictly self-incompatible, while the closely related Arabidopsis thaliana has transitioned to self-compatibility with the loss of functional S-locus genes during evolution. The downstream signaling protein, ARC1, is also required for the self-incompatibility response in some Arabidopsis and Brassica species, and its gene is deleted in the A. thaliana genome. In this study, we attempted to reconstitute the SCR-SRK-ARC1 signaling pathway to restore self-incompatibility in A. thaliana using genes from A. halleri and B. napus, respectively. Several of the transgenic A. thaliana lines expressing the A. halleri SCR13-SRK13-ARC1 transgenes displayed self-incompatibility, while all the transgenic A. thaliana lines expressing the B. napus SCR1-SRK1-ARC1 transgenes failed to show any self-pollen rejection. Furthermore, our results showed that the intensity of the self-incompatibility response in transgenic A. thaliana plants was not associated with the expression levels of the transgenes. Thus, this suggests that there are differences between the Arabidopsis and Brassica self-incompatibility signaling pathways, which perhaps points to the existence of other factors downstream of B. napus SRK that are absent in Arabidopsis species.

EbARC1, an E3 Ubiquitin Ligase Gene in Erigeron breviscapus, Confers Self-Incompatibility in Transgenic Arabidopsis thaliana

“…Coexpressing A. lyrate AlSCR-SRK in Sha, Kas-2, and C24 ecotypes could transform SC into SI but not for the Col-0 ecotype [35,36]. Further investigation found that this phenomenon is caused by the mutation of ARC1 rather than S-locus genes [20], which was supported by the fact that expression of SCR-SRK-AlARC1/BnARC1/AhARC1 in Col-0 and Sha could produce significant SI [5,37]. Although A. lyrate, Arabidopsis helleri L., and B. napus belong to Brassicaceae, Arabidopsis and Brassica differentiated about 20-40 million years ago [38].…”

“…Although A. lyrate, Arabidopsis helleri L., and B. napus belong to Brassicaceae, Arabidopsis and Brassica differentiated about 20-40 million years ago [38]. Interestingly, AlARC1/BnARC1/AhARC1 showed the same function in the regulation of SI response [5,14,37], suggesting that the role of ARC1 derived from different species may be conservative. However, up to now, there is no report on whether high expression of ARC1 alone in A. thaliana (Col-0) can transform SC into SI.…”

Expression of Brassica napus GLO1 is sufficient to breakdown artificial self-incompatibility in Arabidopsis thaliana

“…Artificial self-incompatibility in A. thaliana is an ideal system to study and validate compatibility and self-incompatibility genes identified in other related species. BnSCR1 or BnSRK1 have been previously shown to be non-functional in A. thaliana, as expression of BnSCR1-BnSRK1-BnARC1 failed to reconstitute self-incompatibility in self-pollinated A. thaliana (Zhang et al 2019). There are several pieces of evidence that support the idea of differences between Brassica and Arabidopsis self-incompatibility signaling pathways.…”

FERONIA receptor kinase-regulated reactive oxygen species mediate self-incompatibility in Brassica rapa

“…7,[9][10][11][12] ARC1 is phosphorylated by SRK and targets proteins required for compatible (CP) responses for degradation, leading to the blocking of hydration and metabolic activation of self-pollen. 8,[13][14][15][16][17][18][19] Efforts to introduce SI from various Brassicacea into the self-compatible Arabidopsis thaliana [20][21][22][23][24] suggest that more components are likely to be involved for the rejection of self-pollen during SI response in the Brassica family plants.…”