The cuticle is the outer physical barrier of aerial plant surfaces and an important interaction point between plants and the environment. Many environmental stresses affect cuticle formation, yet the regulatory pathwa...The cuticle is the outer physical barrier of aerial plant surfaces and an important interaction point between plants and the environment. Many environmental stresses affect cuticle formation, yet the regulatory pathways involved remain undefined. We used a genetics and gene expression analysis in Arabidopsis thaliana to define an abscisic acid （ABA） signaling loop that positively regulates cuticle formation via the core ABA signaling pathway, including the PYR/PYL receptors, PP2C phosphatase, and SNF1-Related Protein Kinase （SnRK） 2.21SnRK2.3/SnRK2.6. Downstream of the SnRK2 kinases, cuticle formation was not regulated by the ABA-responsive element-binding transcription factors but rather by DEWAX, MYB16, MYB94, and MYB96. Additionally, low air humidity increased cuticle formation independent of the core ABA pathway and cell death/reactive oxygen species signaling attenuated expression of cuticle-biosynthesis genes. In Physcornitrella patens, exogenous ABA suppressed expression of cuticle- related genes, whose Arabidopsis orthologs were ABA-induced. Hence, the mechanisms regulating cuticle formation are conserved but sophisticated in land plants. Signaling specifically related to cuticle deficiency was identified to play a major role in the adaptation of ABA signaling pathway mutants to increased humidity and in modulating their immunity to Botrytis cinerea in Arabidopsis. These results define a cuticle-specific downstream branch in the ABA signaling pathway that regulates responses to the external environment.展开更多
The discovery of cytosolic ABA receptors is an important breakthrough in stomatal research; signaling via these receptors is involved in determining the basal stomatal conductance and stomatal responsiveness. However,...The discovery of cytosolic ABA receptors is an important breakthrough in stomatal research; signaling via these receptors is involved in determining the basal stomatal conductance and stomatal responsiveness. However, the source of ABA in guard cells is still not fully understood. The level of ABA increases in guard cells by de novo synthesis, recycling from inactive conjugates via β-glucosidases BG1 and BG2 and by import, whereas it decreases by hydroxylation, conjugation, and export. ABA importers include the NRT1/PTR family protein AIT1, ATP-binding cassette protein ABCG40, and possibly ABCG22, whereas the DTX family member DTX50 and ABCG25 function as ABA exporters. Here, we review the proteins involved in ABA transport and homeostasis and their physiological role in stomatal regulation. Recent experiments suggest that functional redundancy probably exists among ABA transporters between vascu- lature and guard cells and ABA recycling proteins, as stomatal functioning remained intact in abcg22, abcg25, abcg40, aitl, and bglbg2 mutants. Only the initial response to reduced air humidity was significantly delayed in abcg22. Considering the reports showing autonomous ABA synthesis in guard cells, we discuss that rapid stomatal responses to atmospheric factors might depend primarily on guard cellsynthesized ABA, whereas in the case of long-term soil water deficit, ABA synthesized in the vasculature might have a significant role.展开更多
Vaccinium darrowii is a subtropical wild blueberry species that has been used to breed economically important southern highbush cultivars.The adaptive traits of V.darrowii to subtropical climates can provide valuable ...Vaccinium darrowii is a subtropical wild blueberry species that has been used to breed economically important southern highbush cultivars.The adaptive traits of V.darrowii to subtropical climates can provide valuable information for breeding blueberry and perhaps other plants,especially against the background of global warming.Here,we assembled the V.darrowii genome into 12 pseudochromosomes using Oxford Nanopore long reads complemented with Hi-C scaffolding technologies,and we predicted 41815 genes using RNA-sequencing evidence.Syntenic analysis across three Vaccinium species revealed a highly conserved genome structure,with the highest collinearity between V.darrowii and Vaccinium corymbosum.This conserved genome structure may explain the high fertility observed during crossbreeding of V.darrowii with other blueberry cultivars.Analysis of gene expansion and tandem duplication indicated possible roles for defense-and flowering-associated genes in the adaptation of V.darrowii to the subtropics.Putative SOC1 genes in V.darrowii were identified based on phylogeny and expression analysis.Blueberries are covered in a thick cuticle layer and contain anthocyanins,which confer their powdery blue color.Using RNA sequencing,we delineated the cuticle biosynthesis pathways of Vaccinium species in V.darrowii.This result can serve as a reference for breeding berries whose colors are appealing to customers.The V.darrowii reference genome,together with the unique traits of this species,including its diploid genome,short vegetative phase,and high compatibility in hybridization with other blueberries,make V.darrowii a potential research model for blueberry species.展开更多
文摘The cuticle is the outer physical barrier of aerial plant surfaces and an important interaction point between plants and the environment. Many environmental stresses affect cuticle formation, yet the regulatory pathways involved remain undefined. We used a genetics and gene expression analysis in Arabidopsis thaliana to define an abscisic acid （ABA） signaling loop that positively regulates cuticle formation via the core ABA signaling pathway, including the PYR/PYL receptors, PP2C phosphatase, and SNF1-Related Protein Kinase （SnRK） 2.21SnRK2.3/SnRK2.6. Downstream of the SnRK2 kinases, cuticle formation was not regulated by the ABA-responsive element-binding transcription factors but rather by DEWAX, MYB16, MYB94, and MYB96. Additionally, low air humidity increased cuticle formation independent of the core ABA pathway and cell death/reactive oxygen species signaling attenuated expression of cuticle-biosynthesis genes. In Physcornitrella patens, exogenous ABA suppressed expression of cuticle- related genes, whose Arabidopsis orthologs were ABA-induced. Hence, the mechanisms regulating cuticle formation are conserved but sophisticated in land plants. Signaling specifically related to cuticle deficiency was identified to play a major role in the adaptation of ABA signaling pathway mutants to increased humidity and in modulating their immunity to Botrytis cinerea in Arabidopsis. These results define a cuticle-specific downstream branch in the ABA signaling pathway that regulates responses to the external environment.
文摘The discovery of cytosolic ABA receptors is an important breakthrough in stomatal research; signaling via these receptors is involved in determining the basal stomatal conductance and stomatal responsiveness. However, the source of ABA in guard cells is still not fully understood. The level of ABA increases in guard cells by de novo synthesis, recycling from inactive conjugates via β-glucosidases BG1 and BG2 and by import, whereas it decreases by hydroxylation, conjugation, and export. ABA importers include the NRT1/PTR family protein AIT1, ATP-binding cassette protein ABCG40, and possibly ABCG22, whereas the DTX family member DTX50 and ABCG25 function as ABA exporters. Here, we review the proteins involved in ABA transport and homeostasis and their physiological role in stomatal regulation. Recent experiments suggest that functional redundancy probably exists among ABA transporters between vascu- lature and guard cells and ABA recycling proteins, as stomatal functioning remained intact in abcg22, abcg25, abcg40, aitl, and bglbg2 mutants. Only the initial response to reduced air humidity was significantly delayed in abcg22. Considering the reports showing autonomous ABA synthesis in guard cells, we discuss that rapid stomatal responses to atmospheric factors might depend primarily on guard cellsynthesized ABA, whereas in the case of long-term soil water deficit, ABA synthesized in the vasculature might have a significant role.
基金supported by the Natural Science Foundation of Zhejiang Province(grant LY22C160005)the National Natural Science Foundation of China(grant 31700224)+2 种基金Innovative Scientific and Technological Talents in Henan Province(no.20HASTIT041)the Outstanding Youth Foundation of Henan Province(no.202300410041)as well as a Nanyang Technological University startup grant and the Academy of Finland(decisions 318288 and 319947)to J.S.
文摘Vaccinium darrowii is a subtropical wild blueberry species that has been used to breed economically important southern highbush cultivars.The adaptive traits of V.darrowii to subtropical climates can provide valuable information for breeding blueberry and perhaps other plants,especially against the background of global warming.Here,we assembled the V.darrowii genome into 12 pseudochromosomes using Oxford Nanopore long reads complemented with Hi-C scaffolding technologies,and we predicted 41815 genes using RNA-sequencing evidence.Syntenic analysis across three Vaccinium species revealed a highly conserved genome structure,with the highest collinearity between V.darrowii and Vaccinium corymbosum.This conserved genome structure may explain the high fertility observed during crossbreeding of V.darrowii with other blueberry cultivars.Analysis of gene expansion and tandem duplication indicated possible roles for defense-and flowering-associated genes in the adaptation of V.darrowii to the subtropics.Putative SOC1 genes in V.darrowii were identified based on phylogeny and expression analysis.Blueberries are covered in a thick cuticle layer and contain anthocyanins,which confer their powdery blue color.Using RNA sequencing,we delineated the cuticle biosynthesis pathways of Vaccinium species in V.darrowii.This result can serve as a reference for breeding berries whose colors are appealing to customers.The V.darrowii reference genome,together with the unique traits of this species,including its diploid genome,short vegetative phase,and high compatibility in hybridization with other blueberries,make V.darrowii a potential research model for blueberry species.
