Blue and green shade nets differentially regulate organic acid accumulation in citrus fruit.

Authors

Abdelmonem Elshahat, Yong-Zhong Liu, Essam Elatafi, Abdullah Alebidi, Abebe Assefa Gobena, Hai-Qiang Liu, Yin Luo, Basma Elhendawy, Rohoma Tahir, Sami Ur Rehman, Abdul Baess Keyhani, Rashid S Al-Obeed, Mahmoud Abdel-Sattar

Published in

Frontiers in plant science. Volume 17. Pages 1969799. Epub Oct 14, 2026.

Abstract

Colored shade nets modify orchard microclimate and may influence citrus fruit metabolism and quality. We evaluated their effects on organic acid accumulation in 'Newhall' sweet orange (Citrus sinensis) over two consecutive growing seasons. In the first season, red, yellow, green, and blue nets at 40% and 60% shading were compared with open-field conditions; green 40% and blue 60%, which showed contrasting acidity responses, were evaluated further in the second season. Shade nets reduced photosynthetically active radiation, light intensity, and canopy temperature, increased relative humidity, maintained PSII efficiency, and generally lowered stress-related indicators. Blue 60% maintained the highest citric acid, malic acid, and titratable acidity, whereas green 40% produced the lowest acidity. These patterns were associated with distinct transcriptional responses: blue 60% showed sustained higher CsPH8 expression and stage-specific increases in CS2 and CS1, while green 40% showed higher expression of several organic-acid degradation-related genes, including ACO, ACL3, FUM, and NAD-ME. Correlation analysis further linked lower radiation and temperature, higher relative humidity, and improved PSII performance with greater organic acid accumulation and expression of acid synthesis- and storage-related genes. Collectively, the findings suggest that blue 60% shading is associated with improved organic acid retention through coordinated microclimatic, physiological, and transcriptional responses, supporting its potential for maintaining citrus fruit acidity under warm, high-radiation conditions.

PMID:
42952569
Bibliographic data and abstract were imported from PubMed on 29 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.