Open AccessSecondary amplification of siRNA machinery limits the application of spray‐induced gene silencing
Author(s) -
Song XiuShi,
Gu KaiXin,
Duan XiaoXin,
Xiao XueMei,
Hou YiPing,
Duan YaBing,
Wang JianXin,
Yu Na,
Zhou MingGuo
Publication year - 2018
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12728
Subject(s) - biology , rna silencing , rna interference , gene silencing , small interfering rna , gene , trans acting sirna , rna , genetics
Summary Spray‐induced gene silencing (SIGS) is an innovative strategy for crop protection. However, the mechanism of SIGS is not known. Here, we first demonstrate that secondary small interfering RNA (siRNA) amplification limits the application of SIGS. A myosin5 gene ( Myo5 ) was chosen as the target of SIGS in an agronomically important pathogen— Fusarium asiaticum . Five segments corresponding to the different regions of the Myo5 gene were found to efficiently silence Myo5 , resulting in cell wall defects, life cycle disruption and virulence reduction. Myo5‐8 (one of the Myo5 segments) induced sequence‐specific RNA interference (RNAi) activity in F. asiaticum , F. graminearum , F. tricinctum and F. oxysporum , but not in other fungi, in vitro . Remarkably, the silencing of Myo5 lasted for only 9 h unless the double‐stranded RNA (dsRNA) was continuously supplied, because F. asiaticum is unable to maintain siRNA amplification. After spraying on plants, dsRNAs were more efficiently taken up via the wounded surface. The antifungal activity of dsRNAs taken up by plant cells was higher and longer lasting than that dried onto the plant surface. In contrast with dsRNAs in fungi, dsRNAs in plant cells could efficiently turn into substantial siRNAs via secondary amplification machinery. Our findings provide new implications to develop SIGS as a mainstream disease control strategy against Fusarium and other fungi.