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
Mitogen-activated protein kinase （MAPK） cascades are universal signal transduction modules present in all eukaryotes. In plants, MAPK cascades were shown to regulate cell division, developmental processes, stress re...Mitogen-activated protein kinase （MAPK） cascades are universal signal transduction modules present in all eukaryotes. In plants, MAPK cascades were shown to regulate cell division, developmental processes, stress responses, and hormone pathways. The subgroup A of Arabidopsis MAPKs consists of AtMPK3, AtMPK6, and AtMPK10. AtMPK3 and AtMPK6 are activated by their upstream MAP kinase kinases （MKKs） AtMKK4 and AtMKK5 in response to biotic and abiotic stress. In addition, they were identified as key regulators of stomatal development and patterning. AtMPKIO has long been considered as a pseudo-gene, derived from a gene duplication of AtMPK6. Here we show that AtMPKIO is expressed highly but very transiently in seedlings and at sites of local auxin maxima leaves. MPK10 encodes a functional kinase and interacts with the upstream MAP kinase kinase （MAPKK） AtMKK2. mpklO mutants are delayed in flowering in long-day conditions and in continuous light. Moreover, cotyledons of mpk10 and mkk2 mutants have reduced vein complexity, which can be reversed by inhibiting polar auxin transport （PAT）. Auxin does not affect AtMPKIO expression while treatment with the PAT inhibitor HFCA extends the expression in leaves and reverses the mpklO mutant phenotype. These results suggest that the AtMKK2-AtMPK10 MAPK module regulates venation complexity by altering PAT efficiency.展开更多
(Molecular Plant 14,1508-1524,September 62021)After the original publication of the above article,attentive readers identified errors in Figure 4H that needed correction as follows.Figure 4H contained the erroneous la...(Molecular Plant 14,1508-1524,September 62021)After the original publication of the above article,attentive readers identified errors in Figure 4H that needed correction as follows.Figure 4H contained the erroneous labels“10 DAP(7 DAT),”which should have each read,“7 DAP(4 DAT).”To avoid any confusion and ensure consistency across our figures,we modified some of the Col-0 images in a corrected version of Figure 4H below to resemble the exact same Col-0 images as in Figure 1C.The details of the changes are as follows:rotation(Col-0 Primed,all timepoints;Col-0 Triggered,3 DAP and 5 DAP;Col-0 Primed/triggered,3 DAP and 5 DAP),replacement(Col-0 Triggered,7 DAP),and different cropping(Col-0 Primed/triggered,7 DAP).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.
文摘Mitogen-activated protein kinase （MAPK） cascades are universal signal transduction modules present in all eukaryotes. In plants, MAPK cascades were shown to regulate cell division, developmental processes, stress responses, and hormone pathways. The subgroup A of Arabidopsis MAPKs consists of AtMPK3, AtMPK6, and AtMPK10. AtMPK3 and AtMPK6 are activated by their upstream MAP kinase kinases （MKKs） AtMKK4 and AtMKK5 in response to biotic and abiotic stress. In addition, they were identified as key regulators of stomatal development and patterning. AtMPKIO has long been considered as a pseudo-gene, derived from a gene duplication of AtMPK6. Here we show that AtMPKIO is expressed highly but very transiently in seedlings and at sites of local auxin maxima leaves. MPK10 encodes a functional kinase and interacts with the upstream MAP kinase kinase （MAPKK） AtMKK2. mpklO mutants are delayed in flowering in long-day conditions and in continuous light. Moreover, cotyledons of mpk10 and mkk2 mutants have reduced vein complexity, which can be reversed by inhibiting polar auxin transport （PAT）. Auxin does not affect AtMPKIO expression while treatment with the PAT inhibitor HFCA extends the expression in leaves and reverses the mpklO mutant phenotype. These results suggest that the AtMKK2-AtMPK10 MAPK module regulates venation complexity by altering PAT efficiency.
文摘(Molecular Plant 14,1508-1524,September 62021)After the original publication of the above article,attentive readers identified errors in Figure 4H that needed correction as follows.Figure 4H contained the erroneous labels“10 DAP(7 DAT),”which should have each read,“7 DAP(4 DAT).”To avoid any confusion and ensure consistency across our figures,we modified some of the Col-0 images in a corrected version of Figure 4H below to resemble the exact same Col-0 images as in Figure 1C.The details of the changes are as follows:rotation(Col-0 Primed,all timepoints;Col-0 Triggered,3 DAP and 5 DAP;Col-0 Primed/triggered,3 DAP and 5 DAP),replacement(Col-0 Triggered,7 DAP),and different cropping(Col-0 Primed/triggered,7 DAP).
