Auñón-Calles David, Pinciroli María, Nicolás Emilio, Gil-Izquierdo Angel, Gabaldón José Antonio, Sánchez-Iglesias María Puerto, Carbonell-Barrachina Angel Antonio, Ferreres Federico, García Carlos J, Romero-Trigueros Cristina
Molecular Recognition and Encapsulation Research Group (REM), Health Sciences Department, Universidad Católica de Murcia (UCAM), Campus de los Jerónimos 135, 30107 Guadalupe, Spain.
Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC, University Campus of Espinardo-Edif. 25, 30100 Murcia, Spain.
Int J Mol Sci. 2025 Apr 7;26(7):3450. doi: 10.3390/ijms26073450.
The Panel on Climate Change has predicted an intensification of drought and heat waves. The aim of this study was to determine the physiological response of mandarin trees in a semi-arid area to the effects of a long period of irrigation with saline reclaimed water (RW) and freshwater (FW) in terms of leaf mineral constitution, free amino acids and phytohormone balance, and their influence on yield and fruit quality. Results showed that higher foliar levels of Cl B, Li, and Br were found in the RW treatment. In addition, fruit quality (juice content, soluble solid content, titratable acid, and maturity index) and yield (fruit weight and diameter) parameters and growth canopy were negatively affected by irrigation with RW. Regardless of the treatments, L-alanine (Ala) and proline were the most abundant amino acids, with Ala being described as a majority for the first time in the literature. Concretely, in FW, the total amino acid content was twice as high as the concentration in RW (51,359.46 and 23,833.31 ng g, respectively). The most abundant hormones were 1-Aminocyclopropane-1-carboxylic acid and -zeatin in both treatments. The saline stress response would be reflected in the higher concentration of salicylic and abscisic acids in the leaves of RW trees. In view of the high correlations found in a simplified correlation matrix of (i) Ala with the canopy growth and (ii) the salicylic acid (SA) with most of the evaluated agrometabolic parameters, it can be concluded that the exogenous application of the Ala and SA would increase tree size and could mitigate the effects of salt stress, respectively. However, these treatments could be completed with the external application of ACC since this phytohormone presents the lowest parameter during treatment with RW.
气候变化专门委员会预测干旱和热浪将加剧。本研究的目的是确定半干旱地区柑橘树在长期用再生盐水（RW）和淡水（FW）灌溉的情况下，在叶片矿物质组成、游离氨基酸和植物激素平衡方面的生理反应，以及它们对产量和果实品质的影响。结果表明，RW处理中叶片的Cl、B、Li和Br含量较高。此外，用RW灌溉对果实品质（果汁含量、可溶性固形物含量、可滴定酸和成熟指数）、产量（果实重量和直径）参数以及树冠生长有负面影响。无论处理如何，L-丙氨酸（Ala）和脯氨酸是最丰富的氨基酸，Ala在文献中首次被描述为主要成分。具体而言，在FW中，总氨基酸含量是RW中浓度的两倍（分别为51359.46和23833.31 ng/g）。两种处理中最丰富的激素是1-氨基环丙烷-1-羧酸和玉米素。盐胁迫反应将体现在RW树叶片中水杨酸和脱落酸的浓度较高。鉴于在简化相关矩阵中发现（i）Ala与树冠生长以及（ii）水杨酸（SA）与大多数评估的农业代谢参数之间存在高度相关性，可以得出结论，外源施用Ala和SA分别会增加树体大小并减轻盐胁迫的影响。然而，这些处理可以通过外源施用ACC来完成，因为这种植物激素在用RW处理期间呈现最低参数。
