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Functional Transition In The Floral Receptacle Of The Sacred Lotus (Nelumbo Nucifera): From Thermogenesis To Photosynthesis, R. E. Miller, J. R. Watling, Sharon A. Robinson
Functional Transition In The Floral Receptacle Of The Sacred Lotus (Nelumbo Nucifera): From Thermogenesis To Photosynthesis, R. E. Miller, J. R. Watling, Sharon A. Robinson
Sharon Robinson
The receptacle of the sacred lotus is the main source of heat during the thermogenic stage of floral development. Following anthesis, it enlarges, greens and becomes a fully functional photosynthetic organ. We investigated development of photosynthetic traits during this unusual functional transition. There were two distinct phases of pigment accumulation in receptacles. Lutein and photoprotective xanthophyll cycle pigments accumulated first with 64% and 95% of the maximum, respectively, present prior to anthesis. Lutein epoxide comprised 32% of total carotenoids in yellow receptacles, but declined with development. By contrast, more than 85% of maximum total chlorophyll, β-carotene and Rubisco were produced …
Two Cys Or Not Two Cys? That Is The Question; Alternative Oxidase In The Thermogenic Plant Sacred Lotus, Nicole M. Grant, Yoshihiko Onda, Yusuke Kakizaki, Kkikukatsu Ito, Jennifer R. Watling, Sharon A. Robinson
Two Cys Or Not Two Cys? That Is The Question; Alternative Oxidase In The Thermogenic Plant Sacred Lotus, Nicole M. Grant, Yoshihiko Onda, Yusuke Kakizaki, Kkikukatsu Ito, Jennifer R. Watling, Sharon A. Robinson
Sharon Robinson
Sacred lotus (Nelumbo nucifera) regulates temperature in its floral chamber to 32°C to 35°C across ambient temperatures of 8°C to 40°C with heating achieved through high alternative pathway fluxes. In most alternative oxidase (AOX) isoforms, two cysteine residues, Cys1 and Cys2, are highly conserved and play a role in posttranslational regulation of AOX. Further control occurs via interaction of reduced Cys1 with α-keto acids, such as pyruvate. Here, we report on the in vitro regulation of AOX isolated from thermogenic receptacle tissues of sacred lotus. AOX protein was mostly present in the reduced form, and only a small fraction could …
Synchronicity Of Thermogenic Activity, Alternative Pathway Respiratory Flux, Aox Protein Content, And Carbohydrates In Receptacle Tissues Of Sacred Lotus During Floral Development, Nicole M. Grant, Rebecca E. Miller, Jennifer R. Watling, Sharon A. Robinson
Synchronicity Of Thermogenic Activity, Alternative Pathway Respiratory Flux, Aox Protein Content, And Carbohydrates In Receptacle Tissues Of Sacred Lotus During Floral Development, Nicole M. Grant, Rebecca E. Miller, Jennifer R. Watling, Sharon A. Robinson
Sharon Robinson
The relationships between heat production, alternative oxidase (AOX) pathway flux, AOX protein, and carbohydrates during floral development in Nelumbo nucifera (Gaertn.) were investigated. Three distinct physiological phases were identified: pre-thermogenic, thermogenic, and post-thermogenic. The shift to thermogenic activity was associated with a rapid, 10-fold increase in AOX protein. Similarly, a rapid decrease in AOX protein occurred post-thermogenesis. This synchronicity between AOX protein and thermogenic activity contrasts with other thermogenic plants where AOX protein increases some days prior to heating. AOX protein in thermogenic receptacles was significantly higher than in post-thermogenic and leaf tissues. Stable oxygen isotope measurements confirmed that the …
Contribution Of The Alternative Pathway To Respiration During Thermogenesis In Flowers Of The Sacred Lotus, Jennifer R. Watling, Sharon A. Robinson, Roger S. Seymour
Contribution Of The Alternative Pathway To Respiration During Thermogenesis In Flowers Of The Sacred Lotus, Jennifer R. Watling, Sharon A. Robinson, Roger S. Seymour
Sharon Robinson
We report results from in vivo measurements, using oxygen isotope discrimination techniques, of fluxes through the alternative and cytochrome respiratory pathways in thermogenic plant tissue, the floral receptacle of the sacred lotus (Nelumbo nucifera). Fluxes through both pathways were measured in thermoregulating flowers undergoing varying degrees of thermogenesis in response to ambient temperature. Significant increases in alternative pathway flux were found in lotus receptacles with temperatures 16°C to 20°C above ambient, but not in those with lesser amounts of heating. Alternative pathway flux in the hottest receptacles was 75% of the total respiratory flux. In contrast, fluxes through the cytochrome …