Abstract
Introduction: The growth of evergreen fruit trees is influenced by the interaction of soil nitrogen (N) and leaf amino acid contents. However, information on free amino acid contents in leaves of fruiting and non-fruiting branches during long-term N fertilizer application remains scarce. Methods: Here, a four-year field experiment (2018-2021) in a citrus orchard revealed consistently lower total N and amino acid contents in leaves of fruiting compared to non-fruiting branches. Results and discussion: Appropriate N fertilizer application increased free amino acid and total N contents in leaves of both types of branches and fruits, but excessive amounts led to decreases. Correlation analysis showed that, in the early stage of fruit development, leaves on both types of branches can meet the N requirements of the fruit (R²=0.77 for fruiting, R²=0.82 for non-fruiting). As fruits entered the swelling stage, a significant positive correlation emerged between fruiting branch leaves and fruit total N content (R²=0.68), while the R² for leaves on non-fruiting branches dropped to 0.47, indicating a shift in N supply towards leaves on fruiting branches. Proline and arginine are the most abundant amino acids in these leaves. At fruit maturity, these amino acids account for more than half of the total amino acids in the fruit (29.0% for proline and 22.2% for arginine), highlighting their crucial role in fruit development. Further research is needed to investigate amino acid transport and distribution mechanisms between citrus leaves and fruits.
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Claims 13
Claim · model-written summary
Fruiting branch leaves had lower total nitrogen than non-fruiting branch leaves.
- Organ / stage
- leaves of fruitinge0
- Outcome
- total Ne0
- Direction
- lowere0
- Comparator
- non-fruiting branchese0
- Setting
- citrus orcharde0
CitrusOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a four-year field experiment (2018-2021) in a citrus orchard revealed consistently lower total N and amino acid contents in leaves of fruiting compared to non-fruiting branches”
Claim · model-written summary
Fruiting branch leaves had lower amino acid content than non-fruiting branch leaves.
- Organ / stage
- leaves of fruitinge0
- Outcome
- amino acid contentse0
- Direction
- lowere0
- Comparator
- non-fruiting branchese0
- Setting
- citrus orcharde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a four-year field experiment (2018-2021) in a citrus orchard revealed consistently lower total N and amino acid contents in leaves of fruiting compared to non-fruiting branches”
Claim · model-written summary
Appropriate nitrogen fertilizer increased free amino acid content in both leaf types and fruits.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Appropriate N fertilizer application increased free amino acid and total N contents in leaves of both types of branches and fruits, but excessive amounts led to decreases”
t0“citrus”
Claim · model-written summary
Appropriate nitrogen fertilizer increased total nitrogen in both leaf types and fruits.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Appropriate N fertilizer application increased free amino acid and total N contents in leaves of both types of branches and fruits, but excessive amounts led to decreases”
t0“citrus”
Claim · model-written summary
Excess nitrogen fertilizer decreased free amino acid content.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Appropriate N fertilizer application increased free amino acid and total N contents in leaves of both types of branches and fruits, but excessive amounts led to decreases”
t0“citrus”
Claim · model-written summary
Excess nitrogen fertilizer decreased total nitrogen content.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Appropriate N fertilizer application increased free amino acid and total N contents in leaves of both types of branches and fruits, but excessive amounts led to decreases”
t0“citrus”
Claim · model-written summary
Early fruit development showed an association of fruiting branch leaves with fruit nitrogen requirements, R²=0.77.
- Organ / stage
- leavese0
- Outcome
- N requirements of the fruite0
- Value
- R²=0.77e0
- Qualifier
- early stage of fruit developmente0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in the early stage of fruit development, leaves on both types of branches can meet the N requirements of the fruit (R²=0.77 for fruiting, R²=0.82 for non-fruiting)”
t0“citrus”
Claim · model-written summary
Early fruit development showed an association of non-fruiting branch leaves with fruit nitrogen requirements, R²=0.82.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in the early stage of fruit development, leaves on both types of branches can meet the N requirements of the fruit (R²=0.77 for fruiting, R²=0.82 for non-fruiting)”
t0“citrus”
Claim · model-written summary
At fruit swelling, fruiting branch leaf nitrogen correlated positively with fruit nitrogen, R²=0.68.
- Organ / stage
- fruiting branch leavese0
- Outcome
- fruit total N contente0
- Direction
- positive correlatione0
- Value
- R²=0.68e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“As fruits entered the swelling stage, a significant positive correlation emerged between fruiting branch leaves and fruit total N content (R²=0.68)”
t0“citrus”
Claim · model-written summary
At fruit swelling, the corresponding R² for non-fruiting branch leaves dropped to 0.47.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“while the R² for leaves on non-fruiting branches dropped to 0.47”
t0“citrus”
Claim · model-written summary
Proline and arginine were the most abundant amino acids in the leaves.
- Outcome
- most abundant amino acidse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Proline and arginine are the most abundant amino acids in these leaves”
t0“citrus”
Claim · model-written summary
At fruit maturity, proline accounted for 29.0% of fruit amino acids.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At fruit maturity, these amino acids account for more than half of the total amino acids in the fruit (29.0% for proline and 22.2% for arginine)”
t0“citrus”
Claim · model-written summary
At fruit maturity, arginine accounted for 22.2% of fruit amino acids.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At fruit maturity, these amino acids account for more than half of the total amino acids in the fruit (29.0% for proline and 22.2% for arginine)”
t0“citrus”
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