OsDIS1-mediated stress response pathway in rice

Abstract

Ubiquitin-mediated protein degradation has been well demonstrated as a key regulatory mechanism in response to drought stress in Arabidopsis. However, the biological function of most E3 ligase genes in drought response is still unknown in rice. We recently showed that OsDIS1 (Oryza sativa drought-induced SINA protein 1), a SINA type E3 ligase, is involved in the drought-stress signal transduction in rice. OsDIS1 plays a negative role in drought stress tolerance through the transcriptional regulation of diverse stress-related genes and also possibly through the posttranslational regulation of its interacting protein OsNek6 in rice. Here we also show that OsDIS1 interacts with OsSKIPa, a drought and salt stress positive regulator in rice. Based on these results, we propose a working model for the function of OsDIS1 in regulating the stress signaling pathway in rice.

Figure 1.

Interaction between OsDIS1 and OsSKIPa in yeast and MG132 inhibition of OsSKIPa degradation. (A) The full-length cDNAs of OsDIS1, OsDIS1(H71Y) were cloned into pGBKT7 while the full-length cDNA of OsSKIPa was cloned pGADT7. The derived constructs were transformed into the yeast strain HF7c. The transformed yeast cells were plated onto the SD/-Leu-Trp medium (left), SD/-Leu-Trp-His+4 mM AT medium (middle) and processed for X-gal assay (right). (B) MG132 inhibition of OsSKIPa degradation. The Agrobacterium strain carrying the GFP-OsSKIPa plasmid was infiltrated into Nicotiana benthamiana leaves, 50 μM MG132 was infiltrated into N. benthamiana 24 h before sampling with DMSO as a control. The extracted protein and RNA were used for protein gel blot and RT-PCR analysis, respectively.

Figure 2.

Working model of the OsDIS1-mediated stress pathway in rice