Abstract
Photosynthetic organs of the cereal spike (ear) provide assimilate for grain filling, but their response to drought is poorly understood. In this study, we characterized the drought response of individual organs of the barley spike (awn, lemma, and palea) and compared them with a vegetative organ (fifth leaf). Understanding differences in physiological and metabolic responses between the leaf and spike organs during drought can help us develop high yielding cultivars for environments where terminal drought is prevalent. We exposed barley plants to drought by withholding water for 4 days at the grain filling stage and compared changes in: (1) relative water content (RWC), (2) osmotic potential (Ψ s ), (3) osmotic adjustment (OA), (4) gas exchange, and (5) metabolite content between organs. Drought reduced RWC and Ψ s in all four organs, but the decrease in RWC was greater and there was a smaller change in Ψ s in the fifth leaf than the spike organs. We detected evidence of OA in the awn, lemma, and palea, but not in the fifth leaf. Rates of gas exchange declined more rapidly in the fifth leaf than awn during drought. We identified 18 metabolites but, only ten metabolites accumulated significantly during drought in one or more organs. Among these, proline accumulated in all organs during drought while accumulation of the other metabolites varied between organs. This may suggest that each organ in the same plant uses a different set of osmolytes for drought resistance. Our results suggest that photosynthetic organs of the barley spike maintain higher water content, greater osmotic adjustment, and higher rates of gas exchange than the leaf during drought.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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 9
Claim · model-written summary
Drought reduced relative water content in all four barley organs, more in the fifth leaf than spike organs.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaret0 - Organ / stage
- fifth leafe0
- Treatment
- Droughte0
- Outcome
- RWCe0
- Direction
- reducede0
- Comparator
- spike organse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“Drought reduced RWC and Ψ s in all four organs, but the decrease in RWC was greater and there was a smaller change in Ψ s in the fifth leaf than the spike organs”
Claim · model-written summary
Drought reduced osmotic potential in all four organs, with a smaller change in the fifth leaf.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- fifth leafe0
- Treatment
- Droughte0
- Outcome
- Ψ se0
- Direction
- reducede0
- Comparator
- spike organse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“Drought reduced RWC and Ψ s in all four organs, but the decrease in RWC was greater and there was a smaller change in Ψ s in the fifth leaf than the spike organs”
Claim · model-written summary
The awn, lemma and palea showed osmotic adjustment during drought.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- awn, lemma, and paleae0
- Outcome
- evidence of OAe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“We detected evidence of OA in the awn, lemma, and palea, but not in the fifth leaf”
Claim · model-written summary
The fifth leaf did not show osmotic adjustment.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- fifth leafe0
- Outcome
- not in the fifth leafe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“We detected evidence of OA in the awn, lemma, and palea, but not in the fifth leaf”
Claim · model-written summary
Gas exchange declined faster in the fifth leaf than the awn during drought.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- fifth leafe0
- Treatment
- droughte0
- Outcome
- Rates of gas exchangee0
- Direction
- declinede0
- Comparator
- awne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“Rates of gas exchange declined more rapidly in the fifth leaf than awn during drought”
Claim · model-written summary
Eighteen metabolites were identified.
- Taxon
- barleyHordeum vulgaret0
- Outcome
- metabolitese0
- Value
- 18 metabolitese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“We identified 18 metabolites”
Claim · model-written summary
Ten metabolites accumulated significantly under drought in at least one organ.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- droughte0
- Outcome
- metabolitese0
- Direction
- accumulatede0
- Value
- ten metabolitese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“only ten metabolites accumulated significantly during drought in one or more organs”
Claim · model-written summary
Proline accumulated in every organ during drought.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- droughte0
- Outcome
- prolinee0
- Direction
- accumulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“proline accumulated in all organs during drought”
Claim · model-written summary
Accumulation of other metabolites varied among organs.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- organse0
- Outcome
- accumulation of the other metabolitese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“barley (Hordeum vulgare L.)”
e0“accumulation of the other metabolites varied between organs”
The same questions in other papers
drought · physiology: osmolytes · Hordeum vulgare (barley)Results differ
7 papers in the same direction as this paper · 3 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- negative
- negative
8 papers more in this group
See all 12 papers →drought · physiology: water · Hordeum vulgare (barley)Results differ
27 papers in the same direction as this paper · 9 in the opposite direction
- positive
- positive
- positive
33 papers more in this group
See all 37 papers →drought · physiology: gas exchange · Hordeum vulgare (barley)Positive and negative results
14 papers in the same direction as this paper · 2 in the opposite direction
- no effect
- positive
- positive
13 papers more in this group
See all 17 papers →drought · molecular: metabolites · Hordeum vulgare (barley)Positive and negative results
11 papers in the same direction as this paper · 19 in the opposite direction · 1 reporting no difference from an alternative
- positive
- no effect
- negative
28 papers more in this group
See all 32 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.