Aquaporin OsPIP2;2 links the H2O2 signal and a membrane-anchored transcription factor to promote plant defense

Abstract

To overcome pathogen infection, plants deploy a highly efficient innate immune system, which often uses hydrogen peroxide (H2O2), a versatile reactive oxygen species, to activate downstream defense responses. H2O2 is a potential substrate of aquaporins, the membrane channels that facilitate the transport of small compounds across plasma membranes or organelle membranes. To date, however, the functional relationship between aquaporins and H2O2 in plant immunity is largely undissected. Here, we report that the rice (Oryza sativa) aquaporin OsPIP2;2 transports pathogen-induced apoplastic H2O2 into the cytoplasm to intensify rice resistance against various pathogens. OsPIP2;2-transported H2O2 is required for microbial molecular pattern flg22 to activate the MAPK cascade and to induce the downstream defense responses. In response to flg22, OsPIP2;2 is phosphorylated at the serine residue S125, and therefore gains the ability to transport H2O2. Phosphorylated OsPIP2;2 also triggers the translocation of OsmaMYB, a membrane-anchored MYB transcription factor, into the plant cell nucleus to impart flg22-induced defense responses against pathogen infection. On the contrary, if OsPIP2;2 is not phosphorylated, OsmaMYB remains associated with the plasma membrane, and plant defense responses are no longer induced. These results suggest that OsPIP2;2 positively regulates plant innate immunity by mediating H2O2 transport into the plant cell and mediating the translocation of OsmaMYB from plasma membrane to nucleus.

Arbuscular mycorrhizal fungus alleviates anthracnose disease in tea seedlings

“…The function of ROS, including superoxide anion, H 2 O 2 , and hydroxyl radicals, in the plant resistance to pathogen mainly consists of direct antimicrobial ability, lignification of the cell wall, induction of HR, production of PR proteins, generation of phytoalexins (like flavonoid), and other defense responses ( Shetty et al., 2008 ; Li et al., 2021b ; Feng et al., 2022 ). H 2 O 2 , acting as a signal, can activate downstream defense responses, and recent studies showed that H 2 O 2 signal could be transduced to aquaporins to endow a resistant ability against pest ( Lu et al., 2022 ) and disease ( Zhang et al., 2021 ) in plant. In this paper, the content of superoxide anion was significantly higher in Tc3d than that in other treatments, while the content of H 2 O 2 was the lowest together with the C3d treatment.…”

A comprehensive dynamic immune acetylproteomics profiling induced by Puccinia polysora in maize

“…7 ). Four aquaporins (PIP1–1, PIP2–1, and two isoforms of PIP2–2) involved in pathogen-induced H 2 O 2 transport [ 66 ] were also differentially regulated by Kac (Fig. 6 ).…”

“…7 ). In addition, we found that four aquaporins involved in pathogen-induced H 2 O 2 transport [ 66 ] were also differentially regulated by Kac (Fig. 6 ) These findings suggest that Kac may response to pathogenic attack by regulating the activity of ROS scavenging-related proteins (Fig.…”

Transcriptomic Analysis of Distal Parts of Roots Reveals Potentially Important Mechanisms Contributing to Limited Flooding Tolerance of Canola (Brassica napus) Plants

“…AP2-ERF TFs were upregulated under low oxygen conditions in Arabidopsis , rice, and poplar ( Populus trichocarpa ) [ 30 , 31 ] and shown to regulate genes encoding respiratory enzymes and ROS scavengers [ 32 ]. In addition, some of the TFs may be involved in regulation of aquaporin expression, including MYB [ 33 ] and ERF [ 34 ]. Translucent green, which belongs to the ERF family, was reported to directly regulate the expression of AtTIP1 ; 1 , AtTIP2 ; 3 , and AtPIP2 ; 2 in Arabidopsis [ 34 ], and OsPIP2 ; 2 in Oryza sativa triggers translocation of OsmaMYB TF [ 33 ].…”

“…In addition, some of the TFs may be involved in regulation of aquaporin expression, including MYB [ 33 ] and ERF [ 34 ]. Translucent green, which belongs to the ERF family, was reported to directly regulate the expression of AtTIP1 ; 1 , AtTIP2 ; 3 , and AtPIP2 ; 2 in Arabidopsis [ 34 ], and OsPIP2 ; 2 in Oryza sativa triggers translocation of OsmaMYB TF [ 33 ].…”