Auxin positively regulates nitrogen remobilization in cucumber leaves
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Nitrogen (N) remobilization is an important N metabolic process in plants. The objective of this study was to increase our understanding of the relationship between low N tolerance and N remobilization in cucumber. Two cucumber cultivars, namely D0328 and D0422, were included in the analyses, the former of which displays a stronger capacity for low N tolerance. Source leaf transcriptomes were analyzed, which revealed differentially expressed genes in a number of interesting pathways, including amino acid biosynthesis, tyrosine and tryptophan biosynthesis, plant hormone signal transduction, and E3 ligase activity, implying that these pathways are involved in low N tolerance in cucumber. In agreement with transcriptome data, old D0328 leaves had significantly higher tryptophan and indole-3-acetic acid contents than old D0422 leaves under low N conditions. N remobilization efficiency in old leaves was increased by naphthaleneacetic acid treatment, whereas it was repressed by antiauxins α-(p-chlorophenoxy) isobutyric acid treatment. Taken together, the results of this study demonstrate that auxin promotes N remobilization in cucumber leaves during the reproductive stage of plant development and this positive regulation is associated with low N tolerance in cucumber.
KeywordsAuxin Cucumber Nitrogen Remobilization Tolerance Tryptophan
This work was supported by National Natural Science Foundation of China (No. 31101545); Program for New Century Excellent Talents in Heilongjiang Provincial University (No. 1452G03); University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province (No. UNPYSCT-2015001); ‘Academic backbone’ Project of Northeast Agricultural University (No. 16XG05); ‘Young Talents’ Project of Northeast Agricultural University (No. 14QC07); Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Ministry of Agriculture/Northeast Agricultural University (No. neauhc201601).
- Diaz C, Lemaître T, Christ A, Azzopardi M, Kato Y, Sato F, Morot-Gaudry JF, Le Dily F, Masclaux-Daubresse C (2008) Nitrogen recycling and remobilization are differentially controlled by leaf senescence and development stage in Arabidopsis under low nitrogen nutrition. Plant Physiol 147:1437–1449CrossRefPubMedPubMedCentralGoogle Scholar
- Hannah MA, Caldana C, Steinhauser D, Balbo I, Fernie AR, Willmitzer L (2010) Combined transcript and metabolite profiling of Arabidopsis grown under widely variant growth conditions facilitates the identification of novel metabolite-mediated regulation of gene expression. Plant Physiol 152:2120–2129CrossRefPubMedPubMedCentralGoogle Scholar
- Martin A, Belastegui-Macadam X, Quillere I, Floriot M, Valadier MH, Pommel B, Andrieu B, Donnison I, Hirel B (2005) Nitrogen management and senescence in two maize hybrids differing in the persistence of leaf greenness: agronomic, physiological and molecular aspects. New Phytol 167:483–492CrossRefPubMedGoogle Scholar
- Peoples MB, Freney JR, Mosier AR (1995) Minimizing gaseous losses of nitrogen. In: Bacon PE (eds) Nitrogen fertilization in the environment. Marcel Dekker Inc, New York, pp 565–602Google Scholar
- Yu ML, Qin ZW, Xu JJ, Zhou XY (2011) Screening of cucumber genotypes with low-nitrogen tolerance and its genetic analysis. China Veg 1:46–51 (in Chinese) Google Scholar
- Zhao W, Yang X, Yu H, Jiang W, Sun N, Liu X, Liu X, Zhang X, Wang Y, Gu X (2015) RNA-Seq-Based transcriptome profiling of early nitrogen deficiency response in cucumber seedlings provides new insight into the putative nitrogen regulatory network. Plant Cell Physiol 56:455–467CrossRefPubMedGoogle Scholar