A Pathogen-Inducible Rice NAC Transcription Factor ONAC096 Contributes to Immunity Against Magnaprothe oryzae and Xanthomonas oryzae pv. oryzae by Direct Binding to the Promoters of OsRap2.6, OsWRKY62, and OsPAL1

Abstract

The rice NAC transcriptional factor family harbors 151 members, and some of them play important roles in rice immunity. Here, we report the function and molecular mechanism of a pathogen-inducible NAC transcription factor, ONAC096, in rice immunity against Magnaprothe oryzae and Xanthomonas oryzae pv. oryzae. Expression of ONAC096 was induced by M. oryzae and by abscisic acid and methyl jasmonate. ONAC096 had the DNA binding ability to NAC recognition sequence and was found to be a nucleus-localized transcriptional activator whose activity depended on its C-terminal. CRISPR/Cas9-mediated knockout of ONAC096 attenuated rice immunity against M. oryzae and X. oryzae pv. oryzae as well as suppressed chitin- and flg22-induced reactive oxygen species burst and expression of PTI marker genes OsWRKY45 and OsPAL4; by contrast, overexpression of ONAC096 enhanced rice immunity against these two pathogens and strengthened chitin- or flg22-induced PTI. RNA-seq transcriptomic profiling and qRT-PCR analysis identified a small set of defense and signaling genes that are putatively regulated by ONAC096, and further biochemical analysis validated that ONAC096 could directly bind to the promoters of OsRap2.6, OsWRKY62, and OsPAL1, three known defense and signaling genes that regulate rice immunity. ONAC096 interacts with ONAC066, which is a positive regulator of rice immunity. These results demonstrate that ONAC096 positively contributes to rice immunity against M. oryzae and X. oryzae pv. oryzae through direct binding to the promoters of downstream target genes including OsRap2.6, OsWRKY62, and OsPAL1.

The NAC transcription factor ONAC083 negatively regulates rice immunity against Magnaporthe oryzae by directly activating transcription of the RING‐H2 gene OsRFPH2‐6

“…In rice, 10 NAC TFs have been shown to be involved in immunity against different pathogens (Nakashima et al, 2007; Kaneda et al, 2009; Yoshii et al, 2009, 2010; Sun et al, 2013; Yokotani et al, 2014; Park et al, 2017; Liu et al, 2018; Wang et al, 2018b; Yuan et al, 2019b; Wang et al, 2021; Yuan et al, 2021b). The seven NAC TFs OsNAC6, ONAC60, OsNAC111, ONAC066, ONAC096, ONAC122, and ONAC131 are positive regulators of M. oryzae resistance (Nakashima et al, 2007; Sun et al, 2013; Yokotani et al, 2014; Liu et al, 2018; Wang et al, 2018b, 2021; Yuan et al, 2021b). The present study identified a novel immunity‐related rice NAC TF, ONAC083, as a negative regulator of rice immunity against M. oryzae and chitin‐triggered PTI (Figures 2, 3).…”

“…The function of NAC TFs mainly depends on their binding to relevant cis ‐elements in the promoters of their target genes, and biochemical studies have identified a number of cis ‐elements recognized by NAC TFs. In rice, most of the identified NAC TFs, including STRESS‐RESPONSIVE NAC1 (SNAC1) (Hu et al, 2006), OsNAC2 (Mao et al, 2020), ONAC022 (Hong et al, 2016), ONAC066 (Yuan et al, 2019a), ONAC096 (Wang et al, 2021), OsNAC23 (Li et al, 2022), OsNAC5 and OsNAC6 (Takasaki et al, 2010), were shown to bind to the canonical NAC recognition sequence (NACRS) (Tran et al, 2004). Other reported cis ‐elements for NAC TFs include the JUB1 binding site (JBS) and JBS‐like (JBSL) elements (Wu et al, 2012) by ONAC066 (Yuan et al, 2019a), the ACGCAA element (Zhang et al, 2019) by OsNAC20 and OsNAC26 (Wang et al, 2020), the secondary wall NAC‐binding element (SNBE) by OsSND (Ye et al, 2018), the Mutator‐derived MITE element by ONAC054 (Sakuraba et al, 2020), and the iron deficiency‐responsive cis ‐acting element 2 (IDE2) by IDE‐binding factor 2 (IDEF2) (Ogo et al, 2008).…”

“…OsNAC111 was shown to activate the expression of the defense genes Pathogenesis‐related 2 ( OsPR2 ) and OsPR8 (Yokotani et al, 2014), whereas OsNAC6 was found to target to promoters of LOC_Os01g73200 (encoding a cationic peroxidase) and LOC_Os04g25060 (encoding a protein containing a conserved domain of unknown function (DUF26) domain) (Nakashima et al, 2007). ONAC066 and ONAC096, two phylogenetically related NAC TFs, bind to the NACRS present in the promoters of NINE‐CIS‐EPOXYCAROTENOID DIOXYGENASE 4 ( OsNCED4 ), OsWRKY62 , and OsRap2.6 ( Related to AP2.6 ) (Liu et al, 2018; Wang et al, 2021; Yuan et al, 2021b), the latter two being involved in immunity against M. oryzae and Xoo .…”

MePAL6 regulates lignin accumulation to shape cassava resistance against two-spotted spider mite

“…Overexpression of Ipomoea batatas gene IbPAL1 conferred chlorogenic acid accumulation in sweet potato leaves, which would stimulate secondary xylem cell expansion in stems, and inhibited storage root formation (Yu et al, 2021). The McPAL3 gene in noni fruit (Mofinda citfifolia) was confirmed to be a key gene involved in the accumulation of scopoletin, as consistent change trend between scopoletin content and total PAL activity were detected while the plant was treated with ethylen (Wang, H. et al, 2021). In addition, several groups of transcription factors i.e., MYB (myeloblastosis) (Xie et al, 2020), bHLH (basic helix-loop-helix) (Du et al, 2018) and WRKY (Wang, Q. et al, 2021 ), are also essential for regulating the lignin biosynthesis pathway.…”

Genome-Wide Identification of the NAC Transcription Factors in Gossypium hirsutum and Analysis of Their Responses to Verticillium wilt

“…In rice, NAC60 enhances the defense response to fungus by increasing reactive oxygen species’ (ROS) accumulation, callous deposition, and the upregulation of defense-related genes [ 4 ]. Similarly, the pathogen-inducible rice NAC gene NAC096 contributes to immunity against bacterial and fungal diseases by directly binding to the promoters of defense-related genes [ 5 ]. SlNAP1 , a NAC gene, strongly induced by various stresses in tomato, showed a significantly enhanced defense against leaf speck disease and root-borne bacterial wilt disease by directly activating the transcription of multiple genes involved in salicylic acid (SA) biosynthesis [ 6 ].…”