Leaf senescence is an important developmental process in the plant life cycle and has a significant impact on agriculture.When facing harsh environmental conditions,monocarpic plants often initiate early leaf senes-ce...Leaf senescence is an important developmental process in the plant life cycle and has a significant impact on agriculture.When facing harsh environmental conditions,monocarpic plants often initiate early leaf senes-cence as an adaptive mechanism to ensure a complete life cycle.Upon initiation,the senescence process is fine-tuned through the coordination of both positive and negative regulators.Here,we report that the small secreted peptide CLAVATA3/ESR-RELATED 14(CLE14)functions in the suppression of leaf senescence by regulating ROS homeostasis in Arabidopsis.Expression of the CLE14-encoding gene in leaves was signifi-cantly induced by age,high salinity,abscisic acid(ABA),salicylic acid,and jasmonic acid.CLE14 knockout plants displayed accelerated progression of both natural and salinity-induced leaf senescence,whereas increased CLE14 expression or treatments with synthetic CLE14 peptides delayed senescence.CLE14 pep-tide treatments also delayed ABA-induced senescence in detached leaves.Further analysis showed that over-expression of CLE14 led to reduced.ROS levels in leaves,where higher expression of ROS scavenging genes was detected.Moreover,CLE14 signaling resulted in transcriptional activation of JUB1,a NAC family tran-scription factor previously identified as a negative regulator of senescence.Notably,the delay of leaf senes-cence,reduction in H202 level,and activation of ROS scavenging genes by CLE14 peptides were dependent on JUB1.Collectively,these results suggest that the small peptide CLE14 serves as a novel"brake signal"to regulate age-dependent and stress-induced leaf senescence through JUB1-mediated ROS scavenging.展开更多
The gibberellins(GAs)are phytohormones that play fundamental roles in almost every aspect of plant growth and development.Although GA biosynthetic and signaling pathways are well understood,the mechanisms that control...The gibberellins(GAs)are phytohormones that play fundamental roles in almost every aspect of plant growth and development.Although GA biosynthetic and signaling pathways are well understood,the mechanisms that control GA homeostasis remain largely unclear in plants.Here,we demonstrate that the homeobox transcription factor(TF)HB40 of the HD-Zip family regulates GA content at two additive con-trol levels in Arabidopsis thaliana.We show that HB40 expression is induced by GA and in turn reduces the levels of endogenous bioactive GAs by simultaneously reducing GA biosynthesis and increasing GA deac-tivation.Consistently,HB40 overexpression leads to typical GA-deficiency traits,such as small rosettes,reduced plant height,delayed flowering,and male sterility.By contrast,a loss-of-function hb40 mutation enhances GA-controlled growth.Genome-wide RNA sequencing combined with molecular-genetic ana-lyses revealed that HB40 directly activates the transcription of JUNGBRUNNEN1(JJUB1),a key TF that re-presses growth by suppressing GA biosynthesis and signaling.HB40 also activates genes encoding GA 2-oxidases(GA2oxs),which are major GA-catabolic enzymes.The effect of HB40 on plant growth is ultimately mediated through the induction of nuclear growth-repressing DELLA proteins.Collectively,our results reveal the important role of the HB40-JUB1 regulatory network in controlling GA homeostasis during plant growth.展开更多
基金the National Natural Science Foundation of China(31571494 to Y.G.and 31600991 to Z.L.),Chinathe Central Public-interest Scientific Institution Basal Research Fund,CAAS(2014ZL046 to Y.G.and Y2016PT51 to Z.L.),China+1 种基金the Ministry of Agriculture“948”Program(2013-Z4 to Y.G.)the Agricultural Science and Technology Innovation Program,Chinese Academy of Agricultural Sciences(ASTIP-TRI02 to Y.G.),China.
文摘Leaf senescence is an important developmental process in the plant life cycle and has a significant impact on agriculture.When facing harsh environmental conditions,monocarpic plants often initiate early leaf senes-cence as an adaptive mechanism to ensure a complete life cycle.Upon initiation,the senescence process is fine-tuned through the coordination of both positive and negative regulators.Here,we report that the small secreted peptide CLAVATA3/ESR-RELATED 14(CLE14)functions in the suppression of leaf senescence by regulating ROS homeostasis in Arabidopsis.Expression of the CLE14-encoding gene in leaves was signifi-cantly induced by age,high salinity,abscisic acid(ABA),salicylic acid,and jasmonic acid.CLE14 knockout plants displayed accelerated progression of both natural and salinity-induced leaf senescence,whereas increased CLE14 expression or treatments with synthetic CLE14 peptides delayed senescence.CLE14 pep-tide treatments also delayed ABA-induced senescence in detached leaves.Further analysis showed that over-expression of CLE14 led to reduced.ROS levels in leaves,where higher expression of ROS scavenging genes was detected.Moreover,CLE14 signaling resulted in transcriptional activation of JUB1,a NAC family tran-scription factor previously identified as a negative regulator of senescence.Notably,the delay of leaf senes-cence,reduction in H202 level,and activation of ROS scavenging genes by CLE14 peptides were dependent on JUB1.Collectively,these results suggest that the small peptide CLE14 serves as a novel"brake signal"to regulate age-dependent and stress-induced leaf senescence through JUB1-mediated ROS scavenging.
基金supported by the European Rogional Dovelop-ment Fund Project Center for Experimental Plant Biology(no.CZ.02.1.01/0.00.0/16.0190000738)and the Czech Sc ence Foundation(no.18-10349S).
文摘The gibberellins(GAs)are phytohormones that play fundamental roles in almost every aspect of plant growth and development.Although GA biosynthetic and signaling pathways are well understood,the mechanisms that control GA homeostasis remain largely unclear in plants.Here,we demonstrate that the homeobox transcription factor(TF)HB40 of the HD-Zip family regulates GA content at two additive con-trol levels in Arabidopsis thaliana.We show that HB40 expression is induced by GA and in turn reduces the levels of endogenous bioactive GAs by simultaneously reducing GA biosynthesis and increasing GA deac-tivation.Consistently,HB40 overexpression leads to typical GA-deficiency traits,such as small rosettes,reduced plant height,delayed flowering,and male sterility.By contrast,a loss-of-function hb40 mutation enhances GA-controlled growth.Genome-wide RNA sequencing combined with molecular-genetic ana-lyses revealed that HB40 directly activates the transcription of JUNGBRUNNEN1(JJUB1),a key TF that re-presses growth by suppressing GA biosynthesis and signaling.HB40 also activates genes encoding GA 2-oxidases(GA2oxs),which are major GA-catabolic enzymes.The effect of HB40 on plant growth is ultimately mediated through the induction of nuclear growth-repressing DELLA proteins.Collectively,our results reveal the important role of the HB40-JUB1 regulatory network in controlling GA homeostasis during plant growth.
