Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves.
Plants utilize an innate immune system to protect themselves from disease. While many molecular components of plant innate immunity resemble the innate immunity of animals, plants also have evolved a number of truly unique defense mechanisms, particularly at the physiological level. Plant's fle...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2017-12-01
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| Series: | PLoS Genetics |
| Online Access: | http://europepmc.org/articles/PMC5749873?pdf=render |
| _version_ | 1811201929237233664 |
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| author | O Rahul Patharkar Walter Gassmann John C Walker |
| author_facet | O Rahul Patharkar Walter Gassmann John C Walker |
| author_sort | O Rahul Patharkar |
| collection | DOAJ |
| description | Plants utilize an innate immune system to protect themselves from disease. While many molecular components of plant innate immunity resemble the innate immunity of animals, plants also have evolved a number of truly unique defense mechanisms, particularly at the physiological level. Plant's flexible developmental program allows them the unique ability to simply produce new organs as needed, affording them the ability to replace damaged organs. Here we develop a system to study pathogen-triggered leaf abscission in Arabidopsis. Cauline leaves infected with the bacterial pathogen Pseudomonas syringae abscise as part of the defense mechanism. Pseudomonas syringae lacking a functional type III secretion system fail to elicit an abscission response, suggesting that the abscission response is a novel form of immunity triggered by effectors. HAESA/HAESA-like 2, INFLORESCENCE DEFICIENT IN ABSCISSION, and NEVERSHED are all required for pathogen-triggered abscission to occur. Additionally phytoalexin deficient 4, enhanced disease susceptibility 1, salicylic acid induction-deficient 2, and senescence-associated gene 101 plants with mutations in genes necessary for bacterial defense and salicylic acid signaling, and NahG transgenic plants with low levels of salicylic acid fail to abscise cauline leaves normally. Bacteria that physically contact abscission zones trigger a strong abscission response; however, long-distance signals are also sent from distal infected tissue to the abscission zone, alerting the abscission zone of looming danger. We propose a threshold model regulating cauline leaf defense where minor infections are handled by limiting bacterial growth, but when an infection is deemed out of control, cauline leaves are shed. Together with previous results, our findings suggest that salicylic acid may regulate both pathogen- and drought-triggered leaf abscission. |
| first_indexed | 2024-04-12T02:30:13Z |
| format | Article |
| id | doaj.art-ab4d61b2f29c4c6784486a13bbafebec |
| institution | Directory Open Access Journal |
| issn | 1553-7390 1553-7404 |
| language | English |
| last_indexed | 2024-04-12T02:30:13Z |
| publishDate | 2017-12-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Genetics |
| spelling | doaj.art-ab4d61b2f29c4c6784486a13bbafebec2022-12-22T03:51:48ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042017-12-011312e100713210.1371/journal.pgen.1007132Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves.O Rahul PatharkarWalter GassmannJohn C WalkerPlants utilize an innate immune system to protect themselves from disease. While many molecular components of plant innate immunity resemble the innate immunity of animals, plants also have evolved a number of truly unique defense mechanisms, particularly at the physiological level. Plant's flexible developmental program allows them the unique ability to simply produce new organs as needed, affording them the ability to replace damaged organs. Here we develop a system to study pathogen-triggered leaf abscission in Arabidopsis. Cauline leaves infected with the bacterial pathogen Pseudomonas syringae abscise as part of the defense mechanism. Pseudomonas syringae lacking a functional type III secretion system fail to elicit an abscission response, suggesting that the abscission response is a novel form of immunity triggered by effectors. HAESA/HAESA-like 2, INFLORESCENCE DEFICIENT IN ABSCISSION, and NEVERSHED are all required for pathogen-triggered abscission to occur. Additionally phytoalexin deficient 4, enhanced disease susceptibility 1, salicylic acid induction-deficient 2, and senescence-associated gene 101 plants with mutations in genes necessary for bacterial defense and salicylic acid signaling, and NahG transgenic plants with low levels of salicylic acid fail to abscise cauline leaves normally. Bacteria that physically contact abscission zones trigger a strong abscission response; however, long-distance signals are also sent from distal infected tissue to the abscission zone, alerting the abscission zone of looming danger. We propose a threshold model regulating cauline leaf defense where minor infections are handled by limiting bacterial growth, but when an infection is deemed out of control, cauline leaves are shed. Together with previous results, our findings suggest that salicylic acid may regulate both pathogen- and drought-triggered leaf abscission.http://europepmc.org/articles/PMC5749873?pdf=render |
| spellingShingle | O Rahul Patharkar Walter Gassmann John C Walker Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves. PLoS Genetics |
| title | Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves. |
| title_full | Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves. |
| title_fullStr | Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves. |
| title_full_unstemmed | Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves. |
| title_short | Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves. |
| title_sort | leaf shedding as an anti bacterial defense in arabidopsis cauline leaves |
| url | http://europepmc.org/articles/PMC5749873?pdf=render |
| work_keys_str_mv | AT orahulpatharkar leafsheddingasanantibacterialdefenseinarabidopsiscaulineleaves AT waltergassmann leafsheddingasanantibacterialdefenseinarabidopsiscaulineleaves AT johncwalker leafsheddingasanantibacterialdefenseinarabidopsiscaulineleaves |