Inorganic phosphate(Pi)is often limited in soils due to precipitation with iron(Fe)and aluminum(Al).To scavenge heterogeneously distributed phosphorus(P)resources,plants have evolved a local Pi signaling pathway that ...Inorganic phosphate(Pi)is often limited in soils due to precipitation with iron(Fe)and aluminum(Al).To scavenge heterogeneously distributed phosphorus(P)resources,plants have evolved a local Pi signaling pathway that induces malate secretion to solubilize the occluded Fe-P or Al-P oxides.In this study,we show that Pi limitation impaired brassinosteroid signaling and downregulated BRASSINAZOLE-RESISTANT 1(BZR1)expression in Arabidopsis thaliana.Exogenous 2,4-epibrassinolide treatment or constitutive activation of BZR1(in the bzr1-D mutant)significantly reduced primary root growth inhibition under Pi-starvation conditions by downregulating ALUMINUM-ACTIVATED MALATE TRANSPORTER 1(ALMT1)expression and malate secretion.Furthermore,At BZR1 competitively suppressed the activator effect of SENSITIVITY TO PROTON RHIZOTOXICITY 1(STOP1)on ALMT1 expression and malate secretion in Nicotiana benthamiana leaves and Arabidopsis.The ratio of nuclear-localized STOP1 and BZR1 determined ALMT1 expression and malate secretion in Arabidopsis.In addition,BZR1-inhibited malate secretion is conserved in rice(Oryza sativa).Our findings provide insight into plant mechanisms for optimizing the secretion of malate,an important carbon resource,to adapt to Pi-deficiency stress.展开更多
As researchers have gained a better understanding in recent years into the physiological, molecular, and genetic basis of how plants deal with aluminum （AI） toxicity in acid soils prevalent in the tropics and sub-tr...As researchers have gained a better understanding in recent years into the physiological, molecular, and genetic basis of how plants deal with aluminum （AI） toxicity in acid soils prevalent in the tropics and sub-tropics, it has become clear that an important component of these responses is the triggering and regulation of cellular pathways and processes by AI. In this review of plant AI signaling, we begin by summarizing the understanding of physiological mechanisms of AI resistance, which first led researchers to realize that AI stress induces gene expression and modifies protein function during the activation of AI resistance responses. Subsequently, an overview of AI resistance genes and their function provides verification that AI induction of gene expression plays a major role in AI resistance in many plant species. More recent research into the mechanistic basis for Al-induced transcrip- tional activation of resistance genes has led to the identifica- tion of several transcription factors as well as cis-elements in the promoters of AI resistance genes that play a role in greater Al-induced gene expression as well as higher constitutive expression of resistance genes in some plant species. Finally, the post-transcriptional and translational regulation of AI resistance proteins is addressed, where recent research has shown that AI can both directly bind to and alter activity of certain organic acid transporters, and also influence AI resistance proteins indirectly, via protein phosphorylation.展开更多
Sensitive to proton rhizotoxicity 1(STOP1) functions as a crucial regulator of root growth during aluminum(Al) stress. However, how this transcription factor is regulated by Al stress to affect downstream genes expres...Sensitive to proton rhizotoxicity 1(STOP1) functions as a crucial regulator of root growth during aluminum(Al) stress. However, how this transcription factor is regulated by Al stress to affect downstream genes expression is not well understood. To explore the underlying mechanisms of the function and regulation of STOP1, we employed a yeast two hybrid screen to identify STOP1-interacting proteins. The SUMO E3 ligase SIZ1, was found to interact with STOP1 and mainly facilitate its SUMO modification at K40 and K212 residues. Simultaneous introduction of K40 R and K212 R substitutions in STOP1 enhances its transactivation activity to upregulate the expression of aluminum-activated malate transporter 1(ALMT1)via increasing the association with mediator 16(MED16) transcriptional co-activator. Loss of function of SIZ1 causes highly increased expression of ALMT1, thus enhancing Al-induced malate exudation and Al tolerance. Also, we found that the protein level of SIZ1 is reduced in response to Al stress. Genetic evidence demonstrates that STOP1/ALMT1 is epistatic to SIZ1 in regulating root growth response to Al stress. This study suggests a mechanism about how the SIZ1–STOP1–ALMT1 signaling module is involved in root growth response to Al stress.展开更多
Objective： Mitral valve disease tends to be treated with anterolateral minithoracotomy （ALMT） rather than median stemotomy （MS）, as ALMT uses progressively smaller incisions to promote better cosmetic outcomes. T...Objective： Mitral valve disease tends to be treated with anterolateral minithoracotomy （ALMT） rather than median stemotomy （MS）, as ALMT uses progressively smaller incisions to promote better cosmetic outcomes. This meta-analysis quantifies the effects of ALMT on surgical parameters and post-operative outcomes compared with MS. Methods： One randomized controlled study and four case-control studies, published in English from January 1996 to January 2013, were identified and evaluated. Results： ALMT showed a significantly longer cardiopulmonary bypass time （P=0.001） and aortic cross-clamp time （P=0.05） compared with MS. However, the benefits of ALMT were evident as demonstrated by a shorter length of hospital stay （P〈0.00001）. According to operative complications, the onset of new arrhythmias following ALMT decreased significantly as compared with MS （P=0.05）; however, the incidence of peri-operative mortality （P=0.62）, re-operation for bleeding （P=0.37）, neurologic events （P=0.77）, myocardial infarction （P=0.84）, gastrointestinal complications （P=0.89）, and renal insufficiency （P=0.67） were similar to these of MS. Long-term follow-up data were also examined, and revealed equivalent survival and freedom from mitral valve events. Conclusions： Current clinical data suggest that ALMT is a safe and effective alternative to the conventional approach and is associated with better short-term outcomes and a trend towards longer survival.展开更多
基金supported by the National Key Research and Development Program of China(2022YFD1900700)the National Natural Science Foundation of China(32072663)the Opening Project of Guangdong Provincial Key Laboratory of Quality&Safety Risk Assessment for Agroproducts(SZKF202201)。
文摘Inorganic phosphate(Pi)is often limited in soils due to precipitation with iron(Fe)and aluminum(Al).To scavenge heterogeneously distributed phosphorus(P)resources,plants have evolved a local Pi signaling pathway that induces malate secretion to solubilize the occluded Fe-P or Al-P oxides.In this study,we show that Pi limitation impaired brassinosteroid signaling and downregulated BRASSINAZOLE-RESISTANT 1(BZR1)expression in Arabidopsis thaliana.Exogenous 2,4-epibrassinolide treatment or constitutive activation of BZR1(in the bzr1-D mutant)significantly reduced primary root growth inhibition under Pi-starvation conditions by downregulating ALUMINUM-ACTIVATED MALATE TRANSPORTER 1(ALMT1)expression and malate secretion.Furthermore,At BZR1 competitively suppressed the activator effect of SENSITIVITY TO PROTON RHIZOTOXICITY 1(STOP1)on ALMT1 expression and malate secretion in Nicotiana benthamiana leaves and Arabidopsis.The ratio of nuclear-localized STOP1 and BZR1 determined ALMT1 expression and malate secretion in Arabidopsis.In addition,BZR1-inhibited malate secretion is conserved in rice(Oryza sativa).Our findings provide insight into plant mechanisms for optimizing the secretion of malate,an important carbon resource,to adapt to Pi-deficiency stress.
文摘As researchers have gained a better understanding in recent years into the physiological, molecular, and genetic basis of how plants deal with aluminum （AI） toxicity in acid soils prevalent in the tropics and sub-tropics, it has become clear that an important component of these responses is the triggering and regulation of cellular pathways and processes by AI. In this review of plant AI signaling, we begin by summarizing the understanding of physiological mechanisms of AI resistance, which first led researchers to realize that AI stress induces gene expression and modifies protein function during the activation of AI resistance responses. Subsequently, an overview of AI resistance genes and their function provides verification that AI induction of gene expression plays a major role in AI resistance in many plant species. More recent research into the mechanistic basis for Al-induced transcrip- tional activation of resistance genes has led to the identifica- tion of several transcription factors as well as cis-elements in the promoters of AI resistance genes that play a role in greater Al-induced gene expression as well as higher constitutive expression of resistance genes in some plant species. Finally, the post-transcriptional and translational regulation of AI resistance proteins is addressed, where recent research has shown that AI can both directly bind to and alter activity of certain organic acid transporters, and also influence AI resistance proteins indirectly, via protein phosphorylation.
基金supported by the National Natural Science Foundation of China(31470371 and 31770305)by Qingdao's Leading Technology Innovator Projectby Youth Interdisciplinary Science and Innovative Research Groups of Shandong University(2020QNQT014)。
文摘Sensitive to proton rhizotoxicity 1(STOP1) functions as a crucial regulator of root growth during aluminum(Al) stress. However, how this transcription factor is regulated by Al stress to affect downstream genes expression is not well understood. To explore the underlying mechanisms of the function and regulation of STOP1, we employed a yeast two hybrid screen to identify STOP1-interacting proteins. The SUMO E3 ligase SIZ1, was found to interact with STOP1 and mainly facilitate its SUMO modification at K40 and K212 residues. Simultaneous introduction of K40 R and K212 R substitutions in STOP1 enhances its transactivation activity to upregulate the expression of aluminum-activated malate transporter 1(ALMT1)via increasing the association with mediator 16(MED16) transcriptional co-activator. Loss of function of SIZ1 causes highly increased expression of ALMT1, thus enhancing Al-induced malate exudation and Al tolerance. Also, we found that the protein level of SIZ1 is reduced in response to Al stress. Genetic evidence demonstrates that STOP1/ALMT1 is epistatic to SIZ1 in regulating root growth response to Al stress. This study suggests a mechanism about how the SIZ1–STOP1–ALMT1 signaling module is involved in root growth response to Al stress.
文摘Objective： Mitral valve disease tends to be treated with anterolateral minithoracotomy （ALMT） rather than median stemotomy （MS）, as ALMT uses progressively smaller incisions to promote better cosmetic outcomes. This meta-analysis quantifies the effects of ALMT on surgical parameters and post-operative outcomes compared with MS. Methods： One randomized controlled study and four case-control studies, published in English from January 1996 to January 2013, were identified and evaluated. Results： ALMT showed a significantly longer cardiopulmonary bypass time （P=0.001） and aortic cross-clamp time （P=0.05） compared with MS. However, the benefits of ALMT were evident as demonstrated by a shorter length of hospital stay （P〈0.00001）. According to operative complications, the onset of new arrhythmias following ALMT decreased significantly as compared with MS （P=0.05）; however, the incidence of peri-operative mortality （P=0.62）, re-operation for bleeding （P=0.37）, neurologic events （P=0.77）, myocardial infarction （P=0.84）, gastrointestinal complications （P=0.89）, and renal insufficiency （P=0.67） were similar to these of MS. Long-term follow-up data were also examined, and revealed equivalent survival and freedom from mitral valve events. Conclusions： Current clinical data suggest that ALMT is a safe and effective alternative to the conventional approach and is associated with better short-term outcomes and a trend towards longer survival.
