The protein levels in single leaf crops are directly finely regulated using the RDDK-Shld1 system.

The main challenge in post-genome biological research is to identify the function of all proteins.
method to study protein biology function is to disturb its expression level, and then observe the corresponding lysological changes.
Currently, the common methods used in botany studies are to regulate protein expression at the DNA and RNA levels;
In order to solve these problems, Qiu Jinlong of the Institute of Microbiology of the Chinese Academy of Sciences established a technical system for direct regulation of the target protein level in the body through the synthesis of small molecular compounds in the gem leaf model plant amoeba - the RDDK-Shld1 system (Su, et al., 2013, Molecular Plant).
recently, Qiu Jinlong's team made new progress in the study of using the RDDK-Shld1 system to directly fine-tune protein levels in single leaf crops. The
RDDK-Shld1 system introduces an arginine (R) into the amino end of the DD domain (a mutant form of FKBP12 with very low stability), introduces a lysine (K) as a potential ubiquitin receiving group at the nirprosium-based end, forms a new fusion label RDDK, and then fuses a ubiquitin (Figure 1) at the N end of the RDDK label.
RDDK fusion protein in the cell translation process, the N-end of the ubibumo is removed exposed to arginine.
the fusion protein is extremely unstable according to the N-end law and is degraded by the protease.
when the synthetic small molecular compound Shld1 exists, Shld1 binds to the DD domain, stabilizing the RDDK fusion protein and allowing it to accumulate in cells (Figure 1).
the study did not detect leakage expression of RDDK fusion protein in rice and wheat, showing the rigor of the RDDK-Shld1 system in single leaf plants.
Shld1 treatment can induce the accumulation of RDDK fusion protein in rice and wheat, and the accumulation level corresponds to the concentration applied by Shld1.
, Shld1-induced protein accumulation is reversible, i.e. after the removal of Shld1, the fusion protein is gradually degraded to immune imprinting that cannot be detected.
, the RDDK-Shld1 system enables fine space-time regulation of target protein accumulation in single leaf plants.
Further studies have found that the accumulation of herbicide-resistant protein Bar and rice pestilence protein Pid3 can be regulated by the RDDK-Shld1 system, and the Shld1 induced accumulation of RDDK-Bar and RDDK-Pid3 proteins can make the corresponding genetically modified plants have herbicide resistance and rice pestilence resistance respectively, indicating that the RDDK-Shld1 system can be used to directly regulate the function of target proteins in rice and wheat.
Rice and wheat are important food crops, and while the transfer of some foreign genes can significantly improve crop adaptability and food quality, the accumulation of proteins expressed by foreign genes may raise public concerns about genetically modified foods, and the application of the RDDK-Shld1 system can eliminate this concern because there is no accumulation of exogenic proteins without Shld1.
therefore, RDDK-Shld1 system as a new type of direct fine regulation of protein accumulation level technology can not only be an effective tool to study protein function, but also for the development of agricultural biotechnology and genetically modified breeding to provide a strong technical support.
research has been published online in the Journal of Plant Biotechnology.
experiments were mainly carried out by Zhang Jingbo, a master's student in Qiu Jinlong's group, Yu Kangquan, an assistant researcher, and Sun Wei, an experimenter, and Qiu Jinlong was the author of the newsletter.
the genetic transformation of rice and wheat has been greatly assisted by the biotechnology platform of the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences.
research has been funded by the National GeneticAlly Modified Special, the Chinese Academy of Sciences and the National Key Laboratory of Plant Genomics.
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