Chinese Bulletin of Botany ›› 2020, Vol. 55 ›› Issue (3): 270-273.DOI: 10.11983/CBB20070

• COMMENTARY • Previous Articles     Next Articles

Small RNA, No Small Feat: Plants Deploy 22 nt siRNAs to Cope with Environmental Stress

Liang Wu1,*(),Yijun Qi2,*()   

  1. 1College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
    2Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
  • Received:2020-05-01 Accepted:2020-05-02 Online:2020-05-01 Published:2020-07-06
  • Contact: Liang Wu,Yijun Qi

Abstract:

RNAs can be classified into protein-coding RNAs and non-coding RNAs (ncRNAs). Small non-coding RNAs (sRNAs) are generated by Dicer-LIKEs (DCLs) and RNA Dependent RNA Polymerases (RDRs). They are associated with different ARGONAUTE (AGO) effector complexes and play important regulatory roles in diverse biological processes. 21 nt microRNAs (miRNAs) and 24 nt small interfering RNAs (siRNAs) are the most abundant classes of sRNAs in plants. The mechanisms of their biogenesis and functions are well studied. However, the functions of other less abundant sRNAs remain largely unknown. A recent study from Prof. Hongwei Guo's group at Southern University of Science and Technology showed that a class of 22 nt siRNAs is produced by RDR6 and DCL2 when plants are under certain stress conditions, especially upon nitrogen deficiency. These 22 nt siRNAs are loaded into AGO1 and mediate translational repression of target mRNAs including nitrate reductase structural genes NIA1/2, thereby minimizing energy consumption. This work elegantly shows that plants deploy 22 nt siRNAs to achieve a deliberate balance between growth and defense in response to environmental stress.

Key words: Arabidopsis, siRNA, translational repression, environmental stress