Nicotiana attenuata flowers, diurnally open,emit scents and move vertically to interact with nocturnal hawkmoth and day-active hummingbird pollinators. To examine the fitness consequences of these floral rhythms, we c...Nicotiana attenuata flowers, diurnally open,emit scents and move vertically to interact with nocturnal hawkmoth and day-active hummingbird pollinators. To examine the fitness consequences of these floral rhythms, we conducted pollination trials in the plant’s native habitat with phase-shifted flowers of plants silenced in circadian clock genes. The results revealed that some pollination benefits observed under glasshouse conditions were not reproduced under natural field conditions. Floral arrhythmicity increased pollination success by hummingbirds, while reducing those by hawkmoths in the field. Thus, floral circadian rhythms may influence a plant’s fitness by filtering pollinators leading to altered seed set from outcrossed pollen.展开更多
Ecological interactions between flowers and pollinators are all about timing. Flower opening/closing and scent emissions are largely synchronized with pollinator activity, and a circadian clock regulates these rhythms...Ecological interactions between flowers and pollinators are all about timing. Flower opening/closing and scent emissions are largely synchronized with pollinator activity, and a circadian clock regulates these rhythms. However, whether the circadian clock increases a plant＇s reproductive success by regulating these floral rhythms remains untested. Flowers of Nicotiana attenuata, a wild tobacco, diurnally and rhythmically open, emit scent and move vertically through a 140° arc to interact with nocturnal hawkmoths. We tethered flowers to evaluate the importanceof flower positions for Manduca flower position dramatically sexta-mediated pollinations; nfluenced pollination. We examined the pollination success of phase-shifted flowers, silenced in circadian clock genes, NaZTL, NaLHY, and NaTOCI, by RNAi. Circadian rhythms in N. attenuata flowers are responsible for altered seed set from outcrossed pollen.展开更多
Nutrients are distributed unevenly in the soil.Phenotypic plasticity in root growth and proliferation may enable plants to cope with this variation and effectively forage for essential nutrients. However, how micronut...Nutrients are distributed unevenly in the soil.Phenotypic plasticity in root growth and proliferation may enable plants to cope with this variation and effectively forage for essential nutrients. However, how micronutrients shape root architecture of plants in their natural environments is poorly understood. We used a combination of field and laboratory-based assays to determine the capacity of Nicotiana attenuata to direct root growth towards localized nutrient patches in its native environment. Plants growing in nature displayed a particular root phenotype consisting of a single primary root and a few long, shallow lateral roots. Analysis of bulk soil surrounding the lateral roots revealed a strong positive correlation between lateral root placement and micronutrient gradients, including copper, iron and zinc. In laboratory assays, the application of localized micronutrient salts close to lateral root tips led to roots bending in the direction of copper and iron. This form of chemotropism was absent in ethylene and jasmonic acid deficient lines,suggesting that it is controlled in part by these two hormones. This work demonstrates that directed root growth underlies foraging behavior, and suggests that chemotropism and micronutrient-guided root placement are important factors that shape root architecture in nature.展开更多
基金supported by European Research Council advanced grant Clockwork Green(No.293926)to I.T.B.the Global Research Lab program(2012055546)from South Koreathe Max Planck Society
文摘Nicotiana attenuata flowers, diurnally open,emit scents and move vertically to interact with nocturnal hawkmoth and day-active hummingbird pollinators. To examine the fitness consequences of these floral rhythms, we conducted pollination trials in the plant’s native habitat with phase-shifted flowers of plants silenced in circadian clock genes. The results revealed that some pollination benefits observed under glasshouse conditions were not reproduced under natural field conditions. Floral arrhythmicity increased pollination success by hummingbirds, while reducing those by hawkmoths in the field. Thus, floral circadian rhythms may influence a plant’s fitness by filtering pollinators leading to altered seed set from outcrossed pollen.
基金supported by European Research Council advanced grant Clockwork Green (No. 293926) to I.T.B.the Global Research Lab program (2012055546) from the National Research Foundation of Korea+1 种基金Institute for Basic Science (IBS-R021-D1)the Max Planck Society
文摘Ecological interactions between flowers and pollinators are all about timing. Flower opening/closing and scent emissions are largely synchronized with pollinator activity, and a circadian clock regulates these rhythms. However, whether the circadian clock increases a plant＇s reproductive success by regulating these floral rhythms remains untested. Flowers of Nicotiana attenuata, a wild tobacco, diurnally and rhythmically open, emit scent and move vertically through a 140° arc to interact with nocturnal hawkmoths. We tethered flowers to evaluate the importanceof flower positions for Manduca flower position dramatically sexta-mediated pollinations; nfluenced pollination. We examined the pollination success of phase-shifted flowers, silenced in circadian clock genes, NaZTL, NaLHY, and NaTOCI, by RNAi. Circadian rhythms in N. attenuata flowers are responsible for altered seed set from outcrossed pollen.
基金the Max Planck Society,European Research Council Advanced Grant(No.293926 to ITB)Alexander von Humboldt Postdoctoral Research Fellowship (to APF)+1 种基金Brazilian National Council for Research (CNPq grant no.237929/2012-0 to CCMA) for financial support
文摘Nutrients are distributed unevenly in the soil.Phenotypic plasticity in root growth and proliferation may enable plants to cope with this variation and effectively forage for essential nutrients. However, how micronutrients shape root architecture of plants in their natural environments is poorly understood. We used a combination of field and laboratory-based assays to determine the capacity of Nicotiana attenuata to direct root growth towards localized nutrient patches in its native environment. Plants growing in nature displayed a particular root phenotype consisting of a single primary root and a few long, shallow lateral roots. Analysis of bulk soil surrounding the lateral roots revealed a strong positive correlation between lateral root placement and micronutrient gradients, including copper, iron and zinc. In laboratory assays, the application of localized micronutrient salts close to lateral root tips led to roots bending in the direction of copper and iron. This form of chemotropism was absent in ethylene and jasmonic acid deficient lines,suggesting that it is controlled in part by these two hormones. This work demonstrates that directed root growth underlies foraging behavior, and suggests that chemotropism and micronutrient-guided root placement are important factors that shape root architecture in nature.
