Paper · 2026 · Plant Communications

AtMYB2 downstream targets AtMYB48 and AtbHLH68 redundantly regulate cambial cell proliferation and xylem differentiation in Arabidopsis thaliana

Chong Zhang; Xiaorui Guo; Leiqian Sun; et al.

14
claims
28
verbatim quotes
0
citations
2
research areas
✓
Open access

Abstract

Xylem formation involves a series of processes, including cell division of the vascular cambium, xylem cell expansion, secondary cell wall (SCW) deposition, and programmed cell death (PCD). In this study, we identified AtMYB2, AtMYB48, and AtbHLH68 as key regulators of cambial cell proliferation and xylem differentiation in Arabidopsis. Overexpression of AtMYB2 decreases cambial cell numbers and increases xylem cell numbers, whereas loss of AtMYB2 results in the opposite phenotype, indicating that AtMYB2 negatively regulates cambial cell proliferation while positively regulating xylem cell differentiation during xylem formation. Both AtMYB48 and AtbHLH68 are direct targets of AtMYB2 and function as positive regulators of cambial cell proliferation and negative regulators of xylem differentiation. Single mutants of AtMYB48 or AtbHLH68 exhibit only mild phenotypic alterations, whereas the atmyb48 atbhlh68 double mutant displays enhanced defects in xylem development. Notably, overexpression of either gene alone is sufficient to rescue the double mutant phenotype, demonstrating functional redundancy between AtMYB48 and AtbHLH68. Although these two proteins can physically interact, this interaction is dispensable for their regulatory functions in xylem development. Despite their redundancy, AtMYB48 and AtbHLH68 exhibit distinct regulatory preferences in xylem differentiation: AtMYB48 primarily regulates genes associated with SCW deposition and PCD, whereas AtbHLH68 predominantly regulates genes involved in cambial cell proliferation. These findings reveal redundant and partially distinct functions of AtMYB48 and AtbHLH68 downstream of AtMYB2 and provide new insights into the transcriptional network controlling xylem formation.

Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗

The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.

Claims 14

Intervention effectobservedoriginal resultmeasured

Claim · model-written summary

Overexpression of AtMYB2 decreases cambial cell numbers.

Taxon
ArabidopsisArabidopsist0
Treatment
Overexpression of AtMYB2e0
Gene
AtMYB2e0
Outcome
cambial cell numberse0
Direction
decreasese0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“Overexpression of AtMYB2 decreases cambial cell numbers”

✓ located verbatim in the source · abstract, characters 339–394 · show in text ↑
Intervention effectobservedoriginal resultmeasured

Claim · model-written summary

Overexpression of AtMYB2 increases xylem cell numbers.

Taxon
ArabidopsisArabidopsist0
Treatment
Overexpression of AtMYB2e0
Gene
AtMYB2e0
Outcome
xylem cell numberse0
Direction
increasese0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“Overexpression of AtMYB2 decreases cambial cell numbers and increases xylem cell numbers”

✓ located verbatim in the source · abstract, characters 339–427 · show in text ↑
Intervention effectobservedoriginal resultmeasured

Claim · model-written summary

Loss of AtMYB2 results in the opposite phenotype to overexpression.

Taxon
ArabidopsisArabidopsist0
Treatment
loss of AtMYB2e0
Gene
AtMYB2e0
Outcome
phenotypee0
Direction
oppositee0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“whereas loss of AtMYB2 results in the opposite phenotype”

✓ located verbatim in the source · abstract, characters 429–485 · show in text ↑
Mechanismauthor interpretationoriginal resultmeasured

Claim · model-written summary

The authors conclude that AtMYB2 negatively regulates cambial cell proliferation.

Taxon
ArabidopsisArabidopsist0
Gene
AtMYB2e0
Outcome
cambial cell proliferatione0
Direction
negatively regulatese0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“AtMYB2 negatively regulates cambial cell proliferation while positively regulating xylem cell differentiation”

✓ located verbatim in the source · abstract, characters 503–612 · show in text ↑
Mechanismauthor interpretationoriginal resultmeasured

Claim · model-written summary

The authors conclude that AtMYB2 positively regulates xylem cell differentiation.

Taxon
ArabidopsisArabidopsist0
Gene
AtMYB2e0
Outcome
xylem cell differentiatione0
Direction
positively regulatinge0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“AtMYB2 negatively regulates cambial cell proliferation while positively regulating xylem cell differentiation”

✓ located verbatim in the source · abstract, characters 503–612 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

AtMYB48 and AtbHLH68 are direct targets of AtMYB2.

Taxon
ArabidopsisArabidopsist0
Gene
AtMYB48 and AtbHLH68e0
Outcome
direct targets of AtMYB2e0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“Both AtMYB48 and AtbHLH68 are direct targets of AtMYB2”

✓ located verbatim in the source · abstract, characters 637–691 · show in text ↑
Mechanismauthor interpretationoriginal resultmeasured

Claim · model-written summary

AtMYB48 and AtbHLH68 function as positive regulators of cambial cell proliferation.

Taxon
ArabidopsisArabidopsist0
Gene
AtMYB48 and AtbHLH68e0
Outcome
cambial cell proliferatione0
Direction
positive regulatorse0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“Both AtMYB48 and AtbHLH68 are direct targets of AtMYB2 and function as positive regulators of cambial cell proliferation and negative regulators of xylem differentiation”

✓ located verbatim in the source · abstract, characters 637–806 · show in text ↑
Mechanismauthor interpretationoriginal resultmeasured

Claim · model-written summary

AtMYB48 and AtbHLH68 function as negative regulators of xylem differentiation.

Taxon
ArabidopsisArabidopsist0
Gene
AtMYB48 and AtbHLH68e0
Outcome
xylem differentiatione0
Direction
negative regulatorse0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“Both AtMYB48 and AtbHLH68 are direct targets of AtMYB2 and function as positive regulators of cambial cell proliferation and negative regulators of xylem differentiation”

✓ located verbatim in the source · abstract, characters 637–806 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Single mutants of AtMYB48 or AtbHLH68 exhibit only mild phenotypic alterations.

Taxon
ArabidopsisArabidopsist0
Material
Single mutants of AtMYB48 or AtbHLH68e0
Outcome
mild phenotypic alterationse0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“Single mutants of AtMYB48 or AtbHLH68 exhibit only mild phenotypic alterations”

✓ located verbatim in the source · abstract, characters 808–886 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

The atmyb48 atbhlh68 double mutant displays enhanced defects in xylem development.

Taxon
ArabidopsisArabidopsist0
Material
atmyb48 atbhlh68 double mutante0
Outcome
defects in xylem developmente0
Direction
enhancede0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“the atmyb48 atbhlh68 double mutant displays enhanced defects in xylem development”

✓ located verbatim in the source · abstract, characters 896–977 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Overexpression of either AtMYB48 or AtbHLH68 alone rescues the double mutant phenotype, indicating functional redundancy.

Taxon
ArabidopsisArabidopsist0
Treatment
overexpression of either gene alonee0
Gene
AtMYB48 and AtbHLH68e0
Outcome
double mutant phenotypee0
Direction
rescuee0
Comparator
double mutante0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“overexpression of either gene alone is sufficient to rescue the double mutant phenotype, demonstrating functional redundancy between AtMYB48 and AtbHLH68”

✓ located verbatim in the source · abstract, characters 988–1141 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

AtMYB48 and AtbHLH68 can physically interact, but this interaction is dispensable for their regulatory functions in xylem development.

Taxon
ArabidopsisArabidopsist0
Gene
these two proteinse0
Outcome
regulatory functions in xylem developmente0
Qualifier
interaction is dispensablee0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“Although these two proteins can physically interact, this interaction is dispensable for their regulatory functions in xylem development”

✓ located verbatim in the source · abstract, characters 1143–1279 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

AtMYB48 primarily regulates genes associated with secondary cell wall deposition and programmed cell death.

Taxon
ArabidopsisArabidopsist0
Gene
AtMYB48e0
Outcome
genes associated with SCW deposition and PCDe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“AtMYB48 primarily regulates genes associated with SCW deposition and PCD”

✓ located verbatim in the source · abstract, characters 1394–1466 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

AtbHLH68 predominantly regulates genes involved in cambial cell proliferation.

Taxon
ArabidopsisArabidopsist0
Gene
AtbHLH68e0
Outcome
genes involved in cambial cell proliferatione0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Arabidopsis
Arabidopsis · Taxon · picture of the genus (one of its species)Original uploader was Brona at en.wikipedia . User:Roepers at nl.wikipedia · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

t0

“Arabidopsis thaliana”

✓ located verbatim in the source · title, characters 124–144 · show in text ↑
e0

“AtbHLH68 predominantly regulates genes involved in cambial cell proliferation”

✓ located verbatim in the source · abstract, characters 1476–1553 · show in text ↑