a cascade of XX
be composed of XX
continuously replenished
classical feedback
CLV1 receptor complex is bound by
modified with sugars
the pathway responsible for modifying CLV3and its relevance for CLV signaling are unknown
mutants with XX are defective in XX genes
is disrupted
be rescued with
weaker mutants are defective in
extend XX chains
maintain meristem size
a mutation in CLV3 increased fruit sizeduring domestication
uncover a new layer of complexity in thecontrol of plant stem cell proliferation
terminate in flowers and initiate newbranch XX
variation in meristem size can account fordifferences in xx
less appreciated is the role of meristemsize in XX, as well as XX
row number is a major driver of yield.
a maintenance mechanism
meristem maintenance is based on
clv signaling involves binding of XX tocell surface XX that include the receptor kinase clv1 and related LRR receptors
initiate a signaling cascade
restricts WUS expression to prevent stemcell overproliferation through negative feedback
promote CLV3 expression to limit its ownactivity
mutations in CLV pathway genes causemeristem to enlarge
lead to increased shoot and xx, moreflowers, and extra organs in flowers and fruits.
studies on mutants with those phenotypes inXX
have shown that XX
pathway is conserved in dicots and monocots
little is known about the genes andmolecular mechanisms underlying stem cell proliferation in other crops, leavingunanswered whether the CLV pathway or other pathways are important incontrolling meristem size and productivity.
investigate the control of meristem size intomato
mutants have enlarged meristems
explore the genetic control of XX
screen XX population for mutants withincreased inflorescence branching
in contrast to previously characterizedmutants
XX are transformed into highly branched structureswith normal flowers as a result of delay in meristem maturation.
identified six new mutants where branchingwas associated with fascinated flowers having more floral organs than wild-typeflowers.
complementation tests identified two loci
that we designated fab and fin，命名：termed, named
branching in fin mutants was more severethan in fab mutants
developed a highly primary shoot with moreside shoots than wild-type plants
with fin mutants bearing the largest
fruits. bear, 结果 produce, arise, 抚养，raised
as a consequence of additional carpels
designate a strong allele of fin as areference
quantification of floral organs in thecorresponding plants confirmed greater fasciation than in fab plants
in the corresponding plants
analyses of double mutants of
defective in the homolog of XX and XX,respectively
showed additive genetic relationship
indicating that the genes underlying finand fab act separately from the meristem matureation pathway
phenotypes of fab and fin mutants werereminiscent of CLV gene
be reminiscent of 和。。相似，使。。想起
The vegetative
this effect became more pronounced
investigate meristem development in finmutants using SEM and found that
enlarged SAM allowed more leaf XX and thusaxillary branch meristem to development
phenotypic similarities between the fab andfin mutants and the fact that fab and fin double-mutant plants were more fascinatedthan either single mutant alone
a functional link in controlling
to better understand the relationshipbetween these mutants
we compared RNA sequencing profiles from XXand XX
we detected a 2-fold or greater differencein expression for 679 genes
in comparison to wild-type apices
significant overlap among thedifferentially expressed genes
could act in the same pathway
a 25-fold increase in SlCLV3 expression, doubledin XX
be also midly affected in
SlCLV3 expression was upregulated by nearlyfivefold
be maintained, consistent with a minorincrease in XX
notably, two additional genes were alsoupregulated in fin mutants
we validated the expression changes for xx
showed substantial expansion of ,consistent with XX
a mapping strategy
underlying the fab and fin mutants, usingF2 populations derived from crosses with the wild tomato. fab mapped to a325-kb interval on the south arm of chromosome 4 where the closest homolog of
was expressed in all tissue types
sequencing its coding region in the fabmutant identified a missense mutation affecting the kinase domin
Notably, classical, weaklydominant-negative allele encodes the same amino acid change, and plantsheterozygous forthe fabmutation exhibited weak fasciation
fin mapped to a 1.1-Mb region in the middleof chromosome 11 containing 71 genes.
RNA sequencing identified a nonsensemutation in Solyc, encoding a homolog of the recently identified HPAT proteinfamily in Ara.
sanger sequencing of XX from fouradditional fin alleles found a missense mutation and deletions. RT-PCR confirmedthat XX transcripts were absent in plants with the deletion alleles.
thus
be structurally similar to members of XX
catalyze the transfer of XX to XX
be primarily found
in the form of
is reduced in XX and XX double-mutantplants, accounting for a range of growth defects
none of the XX mutants show defects inmeristem size.
none of the available HPAP gene mutantsshow defects in meristem size
fin is one of four HAPT gene homologs intomato and is most similar to XX
be expressed in all tissue types
expressed FIN-GFP fusion proteins in tomatoprotoplasts colocalized with a marker
altered extension xx might explain finmutant phenotype, we measured XX composition of XX
found no differences in XX
did not identify differences in cell wallthickness
meristem enlargement in fin mutants is nota results of changes in extension AA or related cell wall defects
engineered mutants of the tomato CLVpathway are fascinated
is also found on secreted signalingpeptides, including XX
be processed from
the mature from of xx is a XX modified withXX
molecular modeling suggests that the XXchain induces conformational changes that have important effects on binding andspecificity for receptor proteins.
in support of this hypothesis, chemicallysynthesized XX CLV3 interacts in vitro with CLV1 more strongly than unmodified CLV3and can rescue the enlarge meristems of clv3 mutants more effectively whenapplied exogenously.
controls meristem size
we generated four first-generationtransgenic VRISP-slclv3 plants that developed branched inflorescences with fascinatedflowers, closely resembling fin mutants
PCR genotyping and sequencing identifiedinsertions and deletions in proximity toboth sgRNAtarget sequences for all alleles.
in proximity to xx
engineered mutations in Fab and CLV2, ahomolog of CLV2 encoding an LRR receptor-like protein that acts redundantlywith CLV1.
CR-fab and CR-clv2 T0 plants were weakly fascinatedlike fab mutants
we validated fasciation for the XX clvmutants in T1 progeny plants. these findings demonstrate that the function ofthe clv meristem maintenance pathway is conserved in tomato.
the enlarged meristems of fin mutants arein striking contrast to the dramatic upregulation of SlCLE genes, suggestingthat a defect in CLV signaling may be due to a failure to post-translationallyarabinosylate CLV3 and CLE peptides.
dramatic, classical, elite, typical
in support of this hypothesis, XX isreduced when XX is overexpressed in XX
are not equally responsible for XX
modification assays using recombinantlyexpressed FIN or HAPT3 form yeast and tobacco BY-2 cell lines have been unableto detect XX activity on XX, we treated live apices with CLE peptides. if lossof CLE XX causes fin mutant phenotypes, then XX peptides should rescue theenlarged meristems.
grew seedlings in liquid culture in thepresence of a low concerntration of each peptide.
sam from fin seedlings grown with XX weresubstantially reduced in size.
combining XX with XX resulted in a rescueof fin phenotype similar to the observed with XX, implying a role for XX in CLVsignaling.
fab meristems were insensitive to XX,consistent with a defect in transducing XX signals.
these results supports the model that stemcell overproliferation in fin meristems is due to a break in the CLV-WUScircuit, caused by a failure to form XX peptides.
loss of an XX cascade causes fasciation(扁化，簇生)
rescreening XX and a new XX population, weidentified two alleles for fab2, a mildly fasciated and branched mutant thatclosely resembled fab mutants.
positional cloning of fab2 identified a missenseand nonsense mutation in the tomato homolog of XX, encoding a predicted XX inthe XX family
XX with mutantions in XX displaypredominantly unusual diarabinoside chains on extensins, resulting in longer XXand shorter root hairs.
XX in expressed in all tissues andlocalized to colgi like fin.
similar to in fin mutants, the expressionlevels of XX were all upregualted in XX, with XX showing greater than tenfoldupregulation in their expression.
thus, fabs like fin, is a criticalregulator of CLV signaling.
predominantly, mainly, largely, chiefly,primarily, principally, mostly, essentially
先介绍拟南芥中该基因的研究状况，然后说明该表型说明了那些机理（能用研究表型相关）。后来提出番茄中可能的假设。
to test whether the tomato homolog of XXwith XX and XX in tomato clv signaling,
mutated the closest homolog of XX using XX
both were most similar to XX, but only XXencoded a predicted transmembrane domain.
transiently expressed Sl-GFP fusionproteins in tomato protoplasts colocalized with a XX marker.
eight XX plants developed branched XX withxx, with these phenotypes more sever than those of the fab2 mutants, and sequencingidentified a range of indel mutations for all alleles, including a homozygous smalldeletion in one plant. using qRT-PCR, we found that XX were all upregualted, withXX showing more than 15-fold higher expression than in wild type. thus, Fin, XXand XX all function in the tomato ClV pathway.
reminded us of naturally occurringfasciation responsible for XX
the dramatic increase in tomato fruit sizeduring domestication
extreme size
be based on more carpels
in comparison to the invariant bilocularfruits of wild tomatoes and most small-fruited cultivars, large-fruitedvarieties can have eight or more locules.
a large portion of this variation is due tolc and fas, two classical mutations that have synergistic effects on loculenumber and thus fruit size when combined.
be weaker than
is likely due to a regulatory mutationdownstream of wus
has been proposed to affect binding of
downregulates wus in XX
be reported to be caused by loss ofexpression of a xx transcription factor gene
dissect, investigate,
be located on chromosome 11 close to XX,and further dissection of the fas locus identified a 294-Kb inversion withbreakpoints in intron 1 of XX and 1kb upstream of CLV3.
in combination with weak rescue of the fasmutant upon introduction of functional XX, led us to
might also contribute to naturallyoccurring fasciation.
introgression of XX into our standard XXbackground resulted in XX resembling the phenotype for XX plants
introgression of fas into XX produced evenweaker fasciation, with XX, likely owing to the absence of modified loci in thewild species background.
such a weak effect would be consistent witha change in clv3 expression, showed reduced expression of XX in the floralmeristems.
to determine whether clv3 underlies the fasmutant, we carried out transgenic complementation experiments in the sp-fasgenotype.
we generated 18 plants carrying a constructcomprising the SlCLV3 gene with 5.5kb of upstream and 3.5 kb of downstreamregions and all plants were rescued to bilocular, smaller fruits.
in contrast,
comprising, including, encompassing, containing,covering, embracing, involving, consist of, excluding
owing to, due to,
16 plants transformed with a similarconstruct containing 1kb upstream of clv3 did not show reduced locular number.notably, we validated these effects in T1 progeny plants and found that rescueof the fas phenotype cosegregated with the transgene. we therefor conclude thata weak regulatory mutation in clv3 underlies the fas mutant.
uniting forward genetics with CRISPR/Cas9technology, we exposed XX genes as critical new components of the clv pathwaythat are essential to control meristem size.
putative XX
have recently been found to function indiverse processed, including pollen tube growth, root hair elongation, and XX.but/yet, no meristem phenotypes for any XX mutants have been reported.
be critical for xx
members of different families were cooptedto target distinct sets of proteins
in different species and developmentalcontexts.
in support of the hypothesis,
unlike the predominant fasciation phenotypeof fin mutants
suffer from sterility defects
in the context of
stem cell maintenance
addition of complete XX chains on XX andrelated XX
is required to fully activate the conservedXX circuit
in this respect
fasciation in fab2 mutants is weaker thanin fin mutants
and CR plants appear intermediate
the potency of peptide signaling XX increasewith XX chain length.
thus, developmentally programmed or environmentallyinduced changes in XX activity on XX and related XX, could be a mechanism to quantitativelycontrol stem cell proliferation and meristem size.
disrupting the XX circuit has dramaticconsequences for
increased fruit size
be likely the first stage of XX
the synergistic effect of
have largely been responsible for fruitthat exceed 500g.
combining fas with ls in xx enhancesfasciation
fas is due to partial loss of clv3expression and that a regulatory change in wus is the likely cause of lcindicate that
relied on subtle changes in the activity ofthe CLV-WUS circuit.
精细的subtle，
seem to be buffered against large changes
although XX in 拟南芥， xx 在番茄中是另一种情况。典型的讨论句式
although the CLV-WUS circuit in Arabidopsisseems to be buffered against large changes in CLV3 expression, fas mutantsdemonstrate that even a modest decrease in expression can cause a substantialincrease in fruit size, without compromising plant growth and architecture.
considerable, large, extensive,
significant, important, generous, ample, sizable,大的
compromising 妥协
in this respect, 在这方面
be notable that
our collection of CLV pathway mutations
a range of fasciation
multiple ways to manipulate
the sets of genes that can be targeted toachieve this control will extend to other XX genes operating in parallel andcompensatory pathway
explain the extreme fasciation in XX and XXdouble mutants,
the ability to fine-tune CLV signalingcould potentially be exploited to improve crop productivity.
in parallel to the improvement of tomatofruit size by fas, induced weak alleles of a clv2 homolog can increase kernelrow number and a naturally occurring CLV3 mutations in XX could provide increasedseed production.
with the widespread success of XX system inplants, the entir CLV pathway, now including XX genes, can be targeted in manycrops to test whether customized alleles can be benefit breeding.
定制的等位基因
