Phytoplasma SAP11 alters 3-isobutyl-2-methoxypyrazine biosynthesis in Nicotiana benthamiana by suppressing NbOMT1.
Phytoplasmas are bacterial phytopathogens that release virulence effectors into sieve cells and act systemically to affect the physiological and morphological state of host plants to promote successful pathogenesis. We show here that transgenic Nicotiana benthamiana lines expressing the secreted effector SAP11 from Candidatus Phytoplasma mali exhibit an altered aroma phenotype. This phenomenon is correlated with defects in the development of glandular trichomes and the biosynthesis of 3-isobutyl-2-methoxypyrazine (IBMP). IBMP is a volatile organic compound (VOC) synthesized by an O-methyltransferase, via a methylation step, from a non-volatile precursor, 3-isobutyl-2-hydroxypyrazine (IBHP). Based on comparative and functional genomics analyses, NbOMT1, which encodes an O-methyltransferase, was found to be highly suppressed in SAP11-transgenic plants. We further silenced NbOMT1 through virus-induced gene silencing and demonstrated that this enzyme influenced the accumulation of IBMP in N. benthamiana In vitro biochemical analyses also showed that NbOMT1 can catalyse IBHP O-methylation in the presence of S-adenosyl-L-methionine. Our study suggests that the phytoplasma effector SAP11 has the ability to modulate host VOC emissions. In addition, we also demonstrated that SAP11 destabilized TCP transcription factors and suppressed jasmonic acid responses in N. benthamiana These findings provide valuable insights into understanding how phytoplasma effectors influence plant volatiles.
Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taiwan.
Choon Meng
CM
Tan
Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan.
Chia-Hua
CH
Li
Department of Forestry, National Chung Hsing University, Taichung 402, Taiwan.
Nai-Wen
NW
Tsao
Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan.
Li-Wen
LW
Su
Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taiwan.
Yen-Ting
YT
Lu
Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan.
Shu Heng
SH
Chang
Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan.
Yi Yu
YY
Lin
Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan.
Jyun-Cyuan
JC
Liou
Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung 402, Taiwan.
Li-Ching
LC
Hsieh
Department of Applied Zoology, Agricultural Research Institute, Taichung 413, Taiwan.
Jih-Zu
JZ
Yu
Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.
Chiou-Rong
CR
Sheue
Department of Forestry, National Chung Hsing University, Taichung 402, Taiwan.
Sheng-Yang
SY
Wang
Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan.
Chin-Fa
CF
Lee
Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taiwan Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan jyang@nchu.edu.tw.
Jun-Yi
JY
Yang
D015153:Blotting, Western; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D045582:Phytoplasma / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011719:Pyrazines / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000378:metabolism / Q000382:microbiology*; D064201:Trichomes / Q000378:metabolism / Q000502:physiology
D010940:Plant Proteins; D011719:Pyrazines; D008780:Methyltransferases; C034376:2-isobutyl-3-methoxypyrazine
3-Isobutyl-2-methoxypyrazine; Nicotiana benthamiana; O-methyltransferase; SAP11; TCP transcription factor.; effector; phytoplasma