A Quantitative Proteomics Study of Early Heat‐Regulated Proteins by Two‐Dimensional Difference Gel Electrophoresis Identified OsUBP21 as a Negative Regulator of Heat Stress Responses in Rice

Abstract

To understand the early heat shock (HS)-regulated cellular responses that influence the tolerance of rice plant to high environmental temperatures, two-dimensional difference gel electrophoresis (2D-DIGE) is performed to explore the early HS-regulated proteome. Multiple proteins that show abundance changes after 1 and 5 min of HS treatment are identified. Of the early HS-regulated proteins identified, the abundance of a ubiquitin-specific protease, OsUBP21, and its Arabidopsis homolog, AtUBP13, is found to be upregulated by 5 min of HS treatment. Further, knocking the expression of OsUBP21 or AtUBP13 down or out increases the tolerance of rice and Arabidopsis plants to HS stress, suggesting that the function of these ubiquitin-specific proteases in regulating plant HS responses is conserved between monocots and dicots. 2D-DIGE showed a group of proteins are differentially regulated in wild-type and ubp21 mutant after 30 min of HS treatment. Among these proteins, 11 are found to interact directly with OsUBP21; thus, they may be targets of OsUBP21. Future analyses of the roles of these OsUBP21-interacting proteins in plant HS responses will help reveal the protein ubiquitination/deubiquitinationregulated cellular responses induced by HS in rice.

Heterologous expression of heat stress-responsive AtPLC9 confers heat tolerance in transgenic rice

“…Rice (Oryza sativa) is an important staple food crop that are highly sensitive to high temperature stress at every growth stage such as seed germination, growth, and reproduction, particularly during the reproductive and grain-filling stages [18][19][20][21]. High temperatures have been shown to negatively affect rice yield and quality.…”

Genetic Research Progress: Heat Tolerance in Rice

“…OsUBP21-mediated protein deubiquitylation damages the regulation of basic heat tolerance in rice. The down-regulation of OsUBP21 expression improves rice tolerance to HS [ 57 ]. The nitrate transporter OsNRT2.3 is related to nitrogen use efficiency and the yield of rice.…”

“…HS upregulated the transcription level of ubiquitin-specific protein hydrolase OsUBP21 . OsUBP21-mediated protein deubiquitylation harmed the regulation of basic heat tolerance in rice, and down-regulation of OsUBP21 expression could improve rice tolerance to HS [ 57 ]. Protein dynamic balance under HS is closely related to translation regulation, which is related to the normal functions of mRNA, tRNA, and rRNA.…”

“…The overexpression of genes TT1 [ 34 ], ER [ 35 ], OsHTAS [ 37 ], TOGR1 [ 38 ], Sus3 [ 39 ], SLG1 [ 40 ], HTS1 [ 41 ], TT3 [ 42 ], MSD1 [ 44 ], OsANN1 [ 45 ], SNAC3 [ 46 ], OsNTL3 [ 47 ], OsHIRP1 [ 48 ], OsRab7 [ 49 ], OsRGB1 [ 50 ], OsNSUN2 [ 52 ], DPB3-1 [ 53 ], OsCNGC14 and OsCNGC16 [ 51 ] could improve the heat tolerance of rice ( Table 1 ). The heat tolerance of rice can also be improved by RNA interference or knockout of genes TT2 [ 54 ], OsMDHAR4 [ 55 ], OsFBN1 [ 56 ], OsUBP21 [ 57 ], and OsNRT2.3 [ 58 ] ( Table 1 ). Although transgenic rice can improve heat tolerance, the use of transgenic rice is still strongly affected due to public concerns about health and safety, which hinders the application of transgenic technology in practical breeding [ 93 ].…”

Gene Networks Involved in Plant Heat Stress Response and Tolerance

“…In response to heat treatment, the survival rate of SbHCI1 -overexpressed plants was significantly higher than in the corresponding WT plants, indicating that SbHCI1 positively regulated heat stress tolerance. The rice soluble ubiquitin-specific protease (OsUBP21) negatively regulated the heat shock response under heat stress [ 63 ]. Its homologous gene AtUBP13 in Arabidopsis also exhibited protein deubiquitination activity and negatively regulated heat shock response.…”