When fed ad libitum （AL）, ectothermic animals usually grow faster and have higher metabolic rate at higher ambient temperature. However, if food supply is limited, there is an energy tradeoff between growth and meta...When fed ad libitum （AL）, ectothermic animals usually grow faster and have higher metabolic rate at higher ambient temperature. However, if food supply is limited, there is an energy tradeoff between growth and metabolism. Here we hypothesize that for ectothermic animals under food restriction （FR）, high temperature will lead to a high metabolic rate, but growth will slow down to compensate for the high metabolism. We measure the rates of growth and metabolism of 4 cohorts of5th instar hornworms （Manduca sexta larvae） reared at 2 levels of food supply （AL and FR） and 2 temperatures （20 and 30 ℃）. Our results show that, compared to the cohorts reared at 20 ℃, the ones reared at 30 ℃ have high metabolic rates under both AL and FR conditions, but a high growth rate under AL and a low growth rate under FR, supporting this hypothesis.展开更多
PHYTOCHROME-INTERACTING FACTORs （PIFs） are members of the basic helix-loop-helix （bHLH） family of transcription factors in Arabidopsis. Since their discovery in phytochrome-mediated light signaling pathways, recen...PHYTOCHROME-INTERACTING FACTORs （PIFs） are members of the basic helix-loop-helix （bHLH） family of transcription factors in Arabidopsis. Since their discovery in phytochrome-mediated light signaling pathways, recent studies have unraveled new functions of PIFs in integrating multiple signaling pathways not only through their role as transcription factors directly targeting gene expression but also by interacting with diverse groups of factors to optimize plant growth and development. These include endogenous （e.g., hormonal） as well as abiotic （light, circadian, and elevated temperature） and biotic （defense responses） pathways. PIFs interact with key factors in each of these pathways and tailor the outcome of the signal integration among these pathways. This review discusses the roles of PIFs as pivotal signal integrators in regulating plant growth and development.展开更多
文摘When fed ad libitum （AL）, ectothermic animals usually grow faster and have higher metabolic rate at higher ambient temperature. However, if food supply is limited, there is an energy tradeoff between growth and metabolism. Here we hypothesize that for ectothermic animals under food restriction （FR）, high temperature will lead to a high metabolic rate, but growth will slow down to compensate for the high metabolism. We measure the rates of growth and metabolism of 4 cohorts of5th instar hornworms （Manduca sexta larvae） reared at 2 levels of food supply （AL and FR） and 2 temperatures （20 and 30 ℃）. Our results show that, compared to the cohorts reared at 20 ℃, the ones reared at 30 ℃ have high metabolic rates under both AL and FR conditions, but a high growth rate under AL and a low growth rate under FR, supporting this hypothesis.
基金We acknowledge support by grants from the National Institutes of Health （1R01 GM-114297）, National Science Foundation （MCB- 1543813）, U.S.-Israel Binationat Science Foundation （BSF#2015316） to E.H., and Rural Development Administration, Republic of Korea （P J01104001） to J.-I.K.
文摘PHYTOCHROME-INTERACTING FACTORs （PIFs） are members of the basic helix-loop-helix （bHLH） family of transcription factors in Arabidopsis. Since their discovery in phytochrome-mediated light signaling pathways, recent studies have unraveled new functions of PIFs in integrating multiple signaling pathways not only through their role as transcription factors directly targeting gene expression but also by interacting with diverse groups of factors to optimize plant growth and development. These include endogenous （e.g., hormonal） as well as abiotic （light, circadian, and elevated temperature） and biotic （defense responses） pathways. PIFs interact with key factors in each of these pathways and tailor the outcome of the signal integration among these pathways. This review discusses the roles of PIFs as pivotal signal integrators in regulating plant growth and development.
