The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana
Over 75% of crop species produce nectar and are dependent on pollinators to achieve maximum seed set, yet little is known about the mechanisms regulating nectar secretion. The phytohormone jasmonic acid (JA) is recognized to be involved in several plant processes including development and defense. J...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-08-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fpls.2018.01060/full |
| _version_ | 1817992886524837888 |
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| author | Anthony J. Schmitt Rahul Roy Peter M. Klinkenberg Mengyuan Jia Clay J. Carter |
| author_facet | Anthony J. Schmitt Rahul Roy Peter M. Klinkenberg Mengyuan Jia Clay J. Carter |
| author_sort | Anthony J. Schmitt |
| collection | DOAJ |
| description | Over 75% of crop species produce nectar and are dependent on pollinators to achieve maximum seed set, yet little is known about the mechanisms regulating nectar secretion. The phytohormone jasmonic acid (JA) is recognized to be involved in several plant processes including development and defense. JA was also recently shown to positively influence nectar secretion in both floral and extrafloral nectaries. For example, endogenous JA levels peak in flowers just prior to nectar secretion, but the details of how JA regulates nectar secretion have yet to be elucidated. We have found that the octadecanoid pathway does indeed play a role in the production and regulation of floral nectar in Arabidopsis. Null alleles for several JA biosynthesis and response genes had significantly reduced amounts of nectar, as well as altered expression of genes known to be involved in nectar production. We additionally identified crosstalk between the JA and auxin response pathways in nectaries. For example, the nectar-less JA synthesis mutant aos-2 showed no auxin response in nectaries, but both nectar production and the auxin response were restored upon exogenous JA and auxin treatment. Conversely, coi1-1, a JA-Ile-insensitive receptor mutant, displayed no auxin response in nectaries under any circumstance, even in older flowers that produced nectar. Surprisingly, opr3-1, a mutant for 12-oxophytodienoate reductase 3 [an enzyme further down the JA biosynthetic pathway that reduces 12-oxo phytodienoic acid (OPDA)], produced no nectar in newly opened flowers, but did secrete nectar in older flowers. Furthermore, a similar phenotype was observed in coi1-1. Cumulatively, these observations strongly suggest an indispensable role for an octadecanoic acid- and auxin-dependent, but JA- and COI1-dispensible, pathway in regulating nectar production in Arabidopsis. |
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| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-04-14T01:32:07Z |
| publishDate | 2018-08-01 |
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| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-9b365744724b48e0af7891c80ed4ecd32022-12-22T02:20:07ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2018-08-01910.3389/fpls.2018.01060380878The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thalianaAnthony J. SchmittRahul RoyPeter M. KlinkenbergMengyuan JiaClay J. CarterOver 75% of crop species produce nectar and are dependent on pollinators to achieve maximum seed set, yet little is known about the mechanisms regulating nectar secretion. The phytohormone jasmonic acid (JA) is recognized to be involved in several plant processes including development and defense. JA was also recently shown to positively influence nectar secretion in both floral and extrafloral nectaries. For example, endogenous JA levels peak in flowers just prior to nectar secretion, but the details of how JA regulates nectar secretion have yet to be elucidated. We have found that the octadecanoid pathway does indeed play a role in the production and regulation of floral nectar in Arabidopsis. Null alleles for several JA biosynthesis and response genes had significantly reduced amounts of nectar, as well as altered expression of genes known to be involved in nectar production. We additionally identified crosstalk between the JA and auxin response pathways in nectaries. For example, the nectar-less JA synthesis mutant aos-2 showed no auxin response in nectaries, but both nectar production and the auxin response were restored upon exogenous JA and auxin treatment. Conversely, coi1-1, a JA-Ile-insensitive receptor mutant, displayed no auxin response in nectaries under any circumstance, even in older flowers that produced nectar. Surprisingly, opr3-1, a mutant for 12-oxophytodienoate reductase 3 [an enzyme further down the JA biosynthetic pathway that reduces 12-oxo phytodienoic acid (OPDA)], produced no nectar in newly opened flowers, but did secrete nectar in older flowers. Furthermore, a similar phenotype was observed in coi1-1. Cumulatively, these observations strongly suggest an indispensable role for an octadecanoic acid- and auxin-dependent, but JA- and COI1-dispensible, pathway in regulating nectar production in Arabidopsis.https://www.frontiersin.org/article/10.3389/fpls.2018.01060/fullnectarnectariesjasmonic acidauxinF-box proteinsSWEET9 |
| spellingShingle | Anthony J. Schmitt Rahul Roy Peter M. Klinkenberg Mengyuan Jia Clay J. Carter The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana Frontiers in Plant Science nectar nectaries jasmonic acid auxin F-box proteins SWEET9 |
| title | The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana |
| title_full | The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana |
| title_fullStr | The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana |
| title_full_unstemmed | The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana |
| title_short | The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana |
| title_sort | octadecanoid pathway but not coi1 is required for nectar secretion in arabidopsis thaliana |
| topic | nectar nectaries jasmonic acid auxin F-box proteins SWEET9 |
| url | https://www.frontiersin.org/article/10.3389/fpls.2018.01060/full |
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