Abstract
Carbon fixed in source leaves is partitioned between local use and long-distance transport through the phloem to heterotrophic sinks such as roots. Here, we investigated how mild defects in sink phloem differentiation influence whole-plant growth using two Arabidopsis mutants: ops, which exhibits short roots with protophloem differentiation defects, and ops opl2, which displays even shorter roots with combined proto- and metaphloem differentiation defects. Carbon partitioning and phloem transport velocity were compromised in both mutants, with ops opl2 exhibiting stronger effects. Root growth responses to exogenous sucrose highlighted functional differences: only ops opl2 root growth was partially rescued, indicating additional limitations from compromised metaphloem function. Reciprocal grafting confirmed that root growth defects in both mutants are root autonomous. In contrast, source-limited starch mutants with short roots were rescued by sucrose supplementation or by grafting wild-type scions, highlighting that the growth limitation in the roots of phloem mutants is not solely due to carbon shortage. Impaired root phloem also restricted wild-type scion growth, revealing feedback from sink phloem integrity on source activity. Together, these findings show that sink phloem development supports sink function and mediates systemic feedback shaping whole-plant growth. Targeted modulation of sink phloem development could help optimize source-sink relations and improve crop performance.
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Claims 8
Claim · model-written summary
Both Arabidopsis phloem mutants had compromised carbon partitioning, more strongly in ops opl2.
- Taxon
- Arabidopsis
Arabidopsise0 - Material
- ops opl2e0
- Outcome
- Carbon partitioninge1
- Direction
- compromisede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants: ops, which exhibits short roots with protophloem differentiation defects, and ops opl2, which displays even shorter roots with combined proto- and metaphloem differentiation defects”
e1“Carbon partitioning and phloem transport velocity were compromised in both mutants, with ops opl2 exhibiting stronger effects”
Claim · model-written summary
Both phloem mutants had compromised transport velocity, more strongly in ops opl2.
- Taxon
- ArabidopsisArabidopsise0
- Material
- ops opl2e0
- Outcome
- phloem transport velocitye1
- Direction
- compromisede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants: ops, which exhibits short roots with protophloem differentiation defects, and ops opl2, which displays even shorter roots with combined proto- and metaphloem differentiation defects”
e1“Carbon partitioning and phloem transport velocity were compromised in both mutants, with ops opl2 exhibiting stronger effects”
Claim · model-written summary
Exogenous sucrose partially rescued ops opl2 root growth.
- Taxon
- ArabidopsisArabidopsise0
- Material
- ops opl2e0
- Treatment
- exogenous sucrosee1
- Outcome
- root growthe1
- Direction
- partially rescuede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants: ops, which exhibits short roots with protophloem differentiation defects, and ops opl2, which displays even shorter roots with combined proto- and metaphloem differentiation defects”
e1“Root growth responses to exogenous sucrose highlighted functional differences: only ops opl2 root growth was partially rescued”
Claim · model-written summary
Reciprocal grafting showed that root growth defects in ops and ops opl2 were root autonomous.
- Taxon
- ArabidopsisArabidopsise0
- Material
- opse0
- Outcome
- root growth defectse1
- Qualifier
- root autonomouse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants: ops, which exhibits short roots with protophloem differentiation defects, and ops opl2, which displays even shorter roots with combined proto- and metaphloem differentiation defects”
e1“Reciprocal grafting confirmed that root growth defects in both mutants are root autonomous”
Claim · model-written summary
Sucrose supplementation rescued short roots of source-limited starch mutants.
- Taxon
- ArabidopsisArabidopsise0
- Material
- source-limited starch mutantse1
- Treatment
- sucrose supplementatione1
- Outcome
- short rootse1
- Direction
- rescuede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants”
e1“source-limited starch mutants with short roots were rescued by sucrose supplementation or by grafting wild-type scions”
Claim · model-written summary
Wild-type scion grafting rescued short roots of source-limited starch mutants.
- Taxon
- ArabidopsisArabidopsise0
- Material
- source-limited starch mutantse1
- Treatment
- grafting wild-type scionse1
- Outcome
- short rootse1
- Direction
- rescuede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants”
e1“source-limited starch mutants with short roots were rescued by sucrose supplementation or by grafting wild-type scions”
Claim · model-written summary
Impaired root phloem restricted growth of wild-type scions.
- Taxon
- ArabidopsisArabidopsise0
- Organ / stage
- root phloeme1
- Outcome
- wild-type scion growthe1
- Direction
- restrictede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants”
e1“Impaired root phloem also restricted wild-type scion growth”
Claim · model-written summary
The authors suggest targeted modulation of sink phloem development to improve crop performance.
- Taxon
- ArabidopsisArabidopsise0
- Outcome
- Targeted modulation of sink phloem developmente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“two Arabidopsis mutants”
e1“Targeted modulation of sink phloem development could help optimize source-sink relations and improve crop performance”
The same questions in other papers
sucrose · growth · ArabidopsisPositive and negative results
8 papers in the same direction as this paper · 8 in the opposite direction
- negative
- negative
- negative
13 papers more in this group
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