- Juan A. López-Ráez (1)
- María A. Peláez-Vico (1)
- Aad Ast van (1)
- Lydia Bernabéu-Roda (1)
- Maurizio Camagna (1)
- Tatsiana Charnikhova (1)
- Nasr Eldin Mohemed Ahmed Mohamed (1)
- Katharina Gaus (2)
- Abdelgabar Gt Babiker (1)
- Michael H. Walter (1)
- Evert J. Bakker (1)
- Harro J. Bouwmeester (3)
- María J. Soto (1)
- Wouter Kohlen (2)
- Alexandre Lumbroso (2)
- Alain Mesmaeker De (1)
- Alain Mesmaeker de (1)
- Carolien P. Ruyter-Spira (2)
- Jean Paul Vincken (2)
- Mark Sanders (2)
- Claudio Screpanti (2)
- Ron Stauder (1)
- Alain Tissier (1)
- Gerd U. Balcke (1)
- Tatsiana V. Charnikhova (2)
- Ralf Welsch (1)
Zeapyranolactone − A novel strigolactone from maize
Charnikhova, Tatsiana V. ; Gaus, Katharina ; Lumbroso, Alexandre ; Sanders, Mark ; Vincken, Jean Paul ; Mesmaeker, Alain De; Ruyter-Spira, Carolien P. ; Screpanti, Claudio ; Bouwmeester, Harro J. - \ 2018
Phytochemistry letters 24 (2018). - ISSN 1874-3900 - p. 172 - 178.
Maize (Zea mays) - NMR - Prep-HPLC–MS - Strigolactones - Zeapyranolactone
The structure of a new strigolactone present in the root exudate and root extract of maize hybrid cv NK Falkone plants was elucidated and characterized as zeapyranolactone: Methyl.(E)-3-((4-methyl-5-oxo-2,5-dihydrofuran-2-yl)oxy)-2-(4,4,5-trimethyl-2-oxo-2,3,4,6,7,7a-hexahydrocyclopenta[b]pyran-7-yl)acrylate. Unlike any other strigolactone published so far, it contains a 4,4-dimethyltetrahydropyran-2-one as A ring. The impact of the elucidation of this structure on the earlier postulated biosynthetic pathway of another maize strigolactone, zealactone, is discussed.
Strigolactone levels in dicot roots are determined by an ancestral symbiosis-regulated clade of the PHYTOENE SYNTHASE gene family
Stauder, Ron ; Welsch, Ralf ; Camagna, Maurizio ; Kohlen, Wouter ; Balcke, Gerd U. ; Tissier, Alain ; Walter, Michael H. - \ 2018
Frontiers in Plant Science 9 (2018). - ISSN 1664-462X
Apocarotenoids - Arbuscular mycorrhiza - Carotenoids - Medicago truncatula - Solanum lycopersicum - Strigolactones - Symbiosis
Strigolactones (SLs) are apocarotenoid phytohormones synthesized from carotenoid precursors. They are produced most abundantly in roots for exudation into the rhizosphere to cope with mineral nutrient starvation through support of root symbionts. Abscisic acid (ABA) is another apocarotenoid phytohormone synthesized in roots, which is involved in responses to abiotic stress. Typically low carotenoid levels in roots raise the issue of precursor supply for the biosynthesis of these two apocarotenoids in this organ. Increased ABA levels upon abiotic stress in Poaceae roots are known to be supported by a particular isoform of phytoene synthase (PSY), catalyzing the rate-limiting step in carotenogenesis. Here we report on novel PSY3 isogenes from Medicago truncatula (MtPSY3) and Solanum lycopersicum (SlPSY3) strongly expressed exclusively upon root interaction with symbiotic arbuscular mycorrhizal (AM) fungi and moderately in response to phosphate starvation. They belong to a widespread clade of conserved PSYs restricted to dicots (dPSY3) distinct from the Poaceae-PSY3s involved in ABA formation. An ancient origin of dPSY3s and a potential co-evolution with the AM symbiosis is discussed in the context of PSY evolution. Knockdown of MtPSY3 in hairy roots of M. truncatula strongly reduced SL and AM-induced C13 α-ionol/C14 mycorradicin apocarotenoids. Inhibition of the reaction subsequent to phytoene synthesis revealed strongly elevated levels of phytoene indicating induced flux through the carotenoid pathway in roots upon mycorrhization. dPSY3 isogenes are coregulated with upstream isogenes and downstream carotenoid cleavage steps toward SLs (D27, CCD7, CCD8) suggesting a combined carotenoid/apocarotenoid pathway, which provides “just in time”-delivery of precursors for apocarotenoid formation.
Zealactones. Novel natural strigolactones from maize
Charnikhova, Tatsiana V. ; Gaus, Katharina ; Lumbroso, Alexandre ; Sanders, Mark ; Vincken, Jean Paul ; Mesmaeker, Alain de; Ruyter-Spira, Carolien P. ; Screpanti, Claudio ; Bouwmeester, Harro J. - \ 2017
Phytochemistry 137 (2017). - ISSN 0031-9422 - p. 123 - 131.
Maize (Zea mays) - NMR - Prep-HPLC-MS - Seed germination - Striga hermonthica (Orobanchaceae) - Strigolactones - UHPLC-MS-MS - Zealactone
In the root exudate and root extracts of maize hybrid cv NK Falkone seven putative strigolactones were detected using UPLC-TQ-MS-MS. All seven compounds displayed MS-MS-fragmentation common for strigolactones and particularly the presence of a fragment of m/z 97 Da, which may indicate the presence of the so-called D-ring, suggests they are strigolactones. The levels of all these putative strigolactones increased upon phosphate starvation and decreased upon fluridone (carotenoid biosynthesis inhibitor) treatment, both of which are a common response for strigolactones. All seven compounds were subsequently isolated with prep-HPLC-MS. They all exhibited Striga hermonthica seed germination inducing activity just as the synthetic strigolactone analog GR24. The structure of two of the seven compounds was elucidated by NMR spectroscopy as: methyl (2E,. 3E)-4-(3,. 3-dimethyl-5-oxo-2-(prop-1-en-2-yl)tetrahydrofuran-2-yl)-2-(((4-methyl-5-oxo-2,. 5-dihydrofuran-2-yl)oxy)methylene)but-3-enoate (two diastereomers 1a and 1b). Strigolactones (1a/b) are closely related to the methyl ester of carlactonoic acid (MeCLA) and heliolactone. However, they contain a unique 4,4-dimethyltetrahydrofuran-2-one motif as the "A-ring" instead of the classical (di)methylcyclohexene. Because these compounds were isolated from maize (Zea mays) we called them "zealactone 1a and 1b". The implications of this discovery for our view on strigolactones and their biosynthesis are discussed.
Evaluation of field resistance to Striga hermonthica (Del.) Benth. in Sorghum bicolor (L.) Moench. The relationship with strigolactones
Mohemed Ahmed Mohamed, Nasr Eldin ; Charnikhova, Tatsiana ; Bakker, Evert J. ; Ast, Aad van; Babiker, Abdelgabar Gt ; Bouwmeester, Harro J. - \ 2016
Pest Management Science 72 (2016)11. - ISSN 1526-498X - p. 2082 - 2090.
Resistance - Sorghum - Striga - Strigolactones
BACKGROUND: Significant losses in sorghum biomass and grain yield occur in sub-Saharan Africa owing to infection by the root-parasitic weed Striga hermonthica (Del.) Benth. One strategy to avoid these losses is to adopt resistant crop varieties. For further delineation of the role of germination stimulants in resistance, we conducted a field experiment employing six sorghum genotypes, in eastern Sudan, and in parallel analysed the strigolactone levels in the root exudates of these genotypes under controlled conditions in Wageningen. RESULTS: The root exudates of these genotypes displayed large differences in strigolactone composition and Striga-germination-inducing activity. Korokollow, Fakimustahi and Wadfahel exuded the highest amounts of 5-deoxystrigol. Fakimustahi was by far the highest sorgomol producer, and Wadbaco and SRN39 produced the highest amount of orobanchol. The concentration of 5-deoxystrigol in the root exudate showed a significant positive correlation with in vitro Striga germination and was positively associated with Striga infection in the field experiments, whereas orobanchol was negatively associated with Striga infection in the field experiments. CONCLUSION: For the first time a close association is reported between strigolactone levels analysed under laboratory conditions and Striga infection in the field in sorghum genotypes. These genotypes may be used for further study of this resistance mechanism and for the introgression of the low germination trait in other sorghum varieties to breed for a strigolactone composition with low stimulant activity. The use of such improved varieties in combination with other Striga management tools could possibly alleviate the current Striga problem on the African continent.
Strigolactones in the Rhizobium-legume symbiosis : Stimulatory effect on bacterial surface motility and down-regulation of their levels in nodulated plants
Peláez-Vico, María A. ; Bernabéu-Roda, Lydia ; Kohlen, Wouter ; Soto, María J. ; López-Ráez, Juan A. - \ 2016
Plant Science 245 (2016). - ISSN 0168-9452 - p. 119 - 127.
Alfalfa - Bacterial motility - Nodulation - Nutrient deficiency - Sinorhizobium meliloti - Strigolactones - Swarming
Strigolactones (SLs) are multifunctional molecules acting as modulators of plant responses under nutrient deficient conditions. One of the roles of SLs is to promote beneficial association with arbuscular mycorrhizal (AM) fungi belowground under such stress conditions, mainly phosphorus shortage. Recently, a role of SLs in the Rhizobium-legume symbiosis has been also described. While SLs' function in AM symbiosis is well established, their role in the Rhizobium-legume interaction is still emerging. Recently, SLs have been suggested to stimulate surface motility of rhizobia, opening the possibility that they could also act as molecular cues. The possible effect of SLs in the motility in the alfalfa symbiont Sinorhizobium meliloti was investigated, showing that the synthetic SL analogue GR24 stimulates swarming motility in S. meliloti in a dose-dependent manner. On the other hand, it is known that SL production is regulated by nutrient deficient conditions and by AM symbiosis. Using the model alfalfa-S. meliloti, the impact of phosphorus and nitrogen deficiency, as well as of nodulation on SL production was also assessed. The results showed that phosphorus starvation promoted SL biosynthesis, which was abolished by nitrogen deficiency. In addition, a negative effect of nodulation on SL levels was detected, suggesting a conserved mechanism of SL regulation upon symbiosis establishment.