Phosphatidylinositol-phospholipase C2 regulates pattern-triggered immunity in Nicotiana benthamiana
Phosphatidylinositol-phospholipase C2 regulates pattern-triggered immunity in Nicotiana benthamiana
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DOI：
10.1093/jxb/eraa233
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发表时间：
2020-08-06
影响因子：
6.9
通讯作者：
Hikichi, Yasufumi
中科院分区：
文献类型：
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作者：
Kiba, Akinori;Nakano, Masahito;Hikichi, Yasufumi
磷脂信号在烟草植物对植物病原菌的免疫应答中起着重要作用。在这里，我们分离到了本氏沼虾基因组中的两个磷脂酶C2(PLC2)同源基因，分别命名为PLC2-1和2-2。NbPLC2-1和NbPLC2-2在大多数组织中都有表达，并在细菌和flg22的诱导下表达。NbPLC2-1和NbPLC2-2(NbPLC2s)双沉默植株表现出中度减慢的生长表型。在NbPLC2s沉默的植株中，NbPLC2s沉默的植株被一株与N.benthamiana相容的青枯雷尔氏菌毒力菌株攻击时，其过敏反应的诱导没有受到影响，但细菌生长和青枯病的出现都被加速了。NbPLC2S沉默植株接种青枯菌后，茉莉酸信号转导标志基因NbPR-4的表达水平降低，茉莉酸和茉莉酸-L异亮氨酸含量降低。在NbPLC2S沉默植株中，青枯菌或荧光假单胞菌渗透后，病原菌相关分子模式(PAMP)触发的免疫(PTI)标记基因的诱导减少。因此，在NbPLC2S沉默的植物中，flg22诱导的抗性被削弱。此外，在沉默的植株中，flg22诱导的PTI标记基因的表达、氧化猝发、气孔关闭和愈伤组织沉积都减少了。因此，NbPLC2可能在侵袭前和侵袭后的防御中发挥重要作用，即在PTI的诱导中。
Phospholipid signaling plays an important role in plant immune responses against phytopathogenic bacteria in Nicotiana benthamiana. Here, we isolated two phospholipase C2 (PLC2) orthologs in the N. benthamiana genome, designated as PLC2-1 and 2-2. Both NbPLC2-1 and NbPLC2-2 were expressed in most tissues and were induced by infiltration with bacteria and flg22. NbPLC2-1 and NbPLC2-2 (NbPLC2s) double-silenced plants showed a moderately reduced growth phenotype. The induction of the hypersensitive response was not affected, but bacterial growth and the appearance of bacterial wilt were accelerated in NbPLC2s-silenced plants when they were challenged with a virulent strain of Ralstonia solanacearum that was compatible with N. benthamiana. NbPLC2s-silenced plants showed reduced expression levels of NbPR-4, a marker gene for jasmonic acid signaling, and decreased jasmonic acid and jasmonoyl-L-isoleucine contents after inoculation with R. solanacearum. The induction of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) marker genes was reduced in NbPLC2s-silenced plants after infiltration with R. solanacearum or Pseudomonas fluorescens. Accordingly, the resistance induced by flg22 was compromised in NbPLC2s-silenced plants. In addition, the expression of flg22-induced PTI marker genes, the oxidative burst, stomatal closure, and callose deposition were all reduced in the silenced plants. Thus, NbPLC2s might have important roles in pre- and post-invasive defenses, namely in the induction of PTI.