In plants, the shoot apical meristem (SAM) is essential for the growth of aboveground organs. However, little is known about its molecular responses to abiotic stresses. Here, we show that the SAM of Arabidopsis thali...In plants, the shoot apical meristem (SAM) is essential for the growth of aboveground organs. However, little is known about its molecular responses to abiotic stresses. Here, we show that the SAM of Arabidopsis thaliana displays an autonomous heat-stress (HS) memory of a previous non-lethal HS, allowing the SAM to regain growth after exposure to an otherwise lethal HS several days later. Using RNA sequencing, we identified genes participating in establishing the SAM's HS transcriptional memory, including the stem cell (SC) regulators CLAVATA1 (CLV1) and CLV3, HEAT SHOCK PROTEIN 17.6A (HSP17.6A), and the primary carbohydrate metabolism gene FRUCTOSE-BISPHOSPHATE ALDOLASE 6 (FBA6). We demonstrate that sugar availability is essential for survival of plants at high temperature. HEAT SHOCK TRANSCRIPTION FACTOR A2 (HSFA2A) directly regulates the expression of HSP17.6A and FBA6 by binding to the heat-shock elements in their promoters, indicating that HSFA2 is required for transcriptional activation of SAM memory genes. Collectively, these findings indicate that plants have evolved a sophisticated protection mechanism to maintain SCs and, hence, their capacity to re-initiate shoot growth after stress release.展开更多
The sessile plants encounter various stresses;some are prolonged,whereas some others are recurrent.Temperature is crucial for plant growth and development,and plants often encounter adverse high temperature fluctuatio...The sessile plants encounter various stresses;some are prolonged,whereas some others are recurrent.Temperature is crucial for plant growth and development,and plants often encounter adverse high temperature fluctuations(heat stresses)as well as prolonged cold exposure such as seasonal temperature drops in winter when grown in temperate regions.Many plants can remember past temperature stresses to get adapted to adverse local temperature changes to ensure survival and/or reproductive success.Here,we summarize chromatin-based mechanisms underlying acquired thermotolerance or thermomemory in plants and review recent progresses on molecular epigenetic understanding of‘remembering of prolonged cold in winter’or vernalization,a process critical for various over-wintering plants to acquire competence to flower in the coming spring.In addition,perspectives on future study in temperature stress memories of economically-important crops are discussed.展开更多
基金Sequencing datasets are available at the NCBI Sequencing Read Archive, BioProject ID PRJNA505602.
文摘In plants, the shoot apical meristem (SAM) is essential for the growth of aboveground organs. However, little is known about its molecular responses to abiotic stresses. Here, we show that the SAM of Arabidopsis thaliana displays an autonomous heat-stress (HS) memory of a previous non-lethal HS, allowing the SAM to regain growth after exposure to an otherwise lethal HS several days later. Using RNA sequencing, we identified genes participating in establishing the SAM's HS transcriptional memory, including the stem cell (SC) regulators CLAVATA1 (CLV1) and CLV3, HEAT SHOCK PROTEIN 17.6A (HSP17.6A), and the primary carbohydrate metabolism gene FRUCTOSE-BISPHOSPHATE ALDOLASE 6 (FBA6). We demonstrate that sugar availability is essential for survival of plants at high temperature. HEAT SHOCK TRANSCRIPTION FACTOR A2 (HSFA2A) directly regulates the expression of HSP17.6A and FBA6 by binding to the heat-shock elements in their promoters, indicating that HSFA2 is required for transcriptional activation of SAM memory genes. Collectively, these findings indicate that plants have evolved a sophisticated protection mechanism to maintain SCs and, hence, their capacity to re-initiate shoot growth after stress release.
基金supported partly by the National Natural Science Foundation of China(31830049,31721001,and 31970327)the Peking-Tsinghua Joint Center for Life Sciences。
文摘The sessile plants encounter various stresses;some are prolonged,whereas some others are recurrent.Temperature is crucial for plant growth and development,and plants often encounter adverse high temperature fluctuations(heat stresses)as well as prolonged cold exposure such as seasonal temperature drops in winter when grown in temperate regions.Many plants can remember past temperature stresses to get adapted to adverse local temperature changes to ensure survival and/or reproductive success.Here,we summarize chromatin-based mechanisms underlying acquired thermotolerance or thermomemory in plants and review recent progresses on molecular epigenetic understanding of‘remembering of prolonged cold in winter’or vernalization,a process critical for various over-wintering plants to acquire competence to flower in the coming spring.In addition,perspectives on future study in temperature stress memories of economically-important crops are discussed.
