1. Adaptive Responses of Hormones to Nitrogen Deficiency in Citrus sinensis Leaves and Roots.
- Author
-
Hua, Dan, Rao, Rong-Yu, Chen, Wen-Shu, Yang, Hui, Shen, Qian, Lai, Ning-Wei, Yang, Lin-Tong, Guo, Jiuxin, Huang, Zeng-Rong, and Chen, Li-Song
- Subjects
JASMONIC acid ,ABSCISIC acid ,HORMONE deficiencies ,NITROGEN deficiency ,SALICYLIC acid - Abstract
Some citrus orchards in China often experience nitrogen (N) deficiency. For the first time, targeted metabolomics was used to examine N-deficient effects on hormones in sweet orange (Citrus sinensis (L.) Osbeck cv. Xuegan) leaves and roots. The purpose was to validate the hypothesis that hormones play a role in N deficiency tolerance by regulating root/shoot dry weight ratio (R/S), root system architecture (RSA), and leaf and root senescence. N deficiency-induced decreases in gibberellins and indole-3-acetic acid (IAA) levels and increases in cis(+)-12-oxophytodienoic acid (OPDA) levels, ethylene production, and salicylic acid (SA) biosynthesis might contribute to reduced growth and accelerated senescence in leaves. The increased ethylene formation in N-deficient leaves might be caused by increased 1-aminocyclopropanecarboxylic acid and OPDA and decreased abscisic acid (ABA). N deficiency increased R/S, altered RSA, and delayed root senescence by lowering cytokinins, jasmonic acid, OPDA, and ABA levels and ethylene and SA biosynthesis, increasing 5-deoxystrigol levels, and maintaining IAA and gibberellin homeostasis. The unchanged IAA concentration in N-deficient roots involved increased leaf-to-root IAA transport. The different responses of leaf and root hormones to N deficiency might be involved in the regulation of R/S, RSA, and leaf and root senescence, thus improving N use efficiency, N remobilization efficiency, and the ability to acquire N, and hence conferring N deficiency tolerance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF