Reactive oxygen species and nitric oxide induce senescence of rudimentary leaves and the expression profiles of the related genes in Litchi chinensis

Abstract

Litchi is one of the most important subtropical evergreen fruit trees in southern Asia. Previous studies indicated that high-temperature conditions encourage growth of rudimentary leaves in panicles and suppress flowering. We have demonstrated that methyl viologen dichloride hydrate (MV) and sodium nitroprusside (SNP) promoted flowering in litchi partially by inhibiting the growth of rudimentary leaves via reactive oxygen species (ROS) and nitric oxide (NO). In the present study, we examined the microstructure and ultrastructure, programmed cell death (PCD) ratio, nuclei morphology of the rudimentary leaves, and the expression of senescence-related genes after the treatment with ROS or NO. The results showed that chromatins of the ROS- or NO-treated cells in the rudimentary leaves were condensed. Fusion of the cytoplasm-digesting vesicles with the vacuole and degradation of cytoplasm forming scattered debris were found in those of the treated cells. Treatment with ROS or NO increased the cell PCD ratio. Morphology of the nuclei stained by propidium iodide (PI) showed that nuclei shape became irregular after the ROS or NO treatment. Further, the expression levels of LcRboh, LcMC-1-like, and LcPirin were higher in the ROS- and NO-treated rudimentary leaves than those in the control ones, suggesting that these genes may be involved in the ROS and NO-induced senescence and abscission of the rudimentary leaves in litchi. Our results suggested that ROS and NO play an important role in inducing the senescence of the rudimentary leaves, and ROS- and NO-induced PCD may be involved in the regulation of the rudimentary leaf growth in litchi.

References

[1] Menzel, C. M. & Simpson, D. X. Effect of temperature on growth and flowering of litchi (Litchi chinensis Sonn.) cultivars . J. Hortic. Sci. 63, 349-360 (1988).

[2] Chen, H. B. & Huang, H. B. Low temperature requirements for floral induction in lychee. Acta Hortic. 665, 195-202 (2005).

[3] Zhou, B. et al. Rudimentary leaf abortion with the development of panicle in litchi: changes in ultrastructure, antioxidant enzymes and phytohormones. Sci. Hortic. 117, 288-296 (2008).

[4] Kocsy, G. et al. Redox control of plant growth and development. Plant Sci. 211, 77-91 (2013).

[5] Dat, J. et al. Dual action of the active oxygen species during plant stress responses. Cell Mol. Life Sci. 57, 779-795 (2000).

[6] Gould, K. S., Lamotte, O., Klinguer, A., Pugin, A. & Wendehenne, D. Nitric oxide production in tobacco leaf cells: a generalized stress response?. Plant Cell Environ. 26, 1851-1862 (2003).

[7] Corpas, F. J. & Barroso, J. B. Nitro-oxidative stress vs oxidative or nitrosative stress in higher plants. N. Phytol. 199, 633-637 (2013).

[8] Hermes, V. S., Dall’asta, P., Amaral, F. P., Anacleto, K. B. & Arisi, A. The regulation of transcription of genes related to oxidative stress and glutathione synthesis in Zea mays leaves by nitric oxide . Biol. Plant. 57, 620-626 (2013).

[9] Cui, Z. Y. Cloning and Expression Analysis of AP1 and CDPK Homologue Gene in Litchi (Litchi chinensis Sonn.) . Master thesis, South China Agricultural University, College of Horticulture (2010).

[10] Zhou, B. et al. Hydrogen peroxide and nitric oxide promote reproductive growth in Litchi chinensis . Biol. Plant. 56, 321-329 (2012).

[11] Jing, H. et al. Early leaf senescence is associated with an altered cellular redox balance in Arabidopsis cpr5/old1 mutants . Plant Biol. 10, 85-98 (2008).

[12] Wu, X. Y., Kuai, B. K., Jia, J. Z. & Jing, H. C. Regulation of leaf senescence and crop genetic improvement. J. Integr. Plant Biol. 54, 936-952 (2012).

[13] Allu, A. D., Soja, A. M., Wu, A., Szymanski, J. & Balazadeh, S. Salt stress and senescence: identification of cross-talk regulatory components. J. Exp. Bot. 65, 3993-4008 (2014).

[14] Naschitz, S., Naor, A., Wolf, S. & Goldschmidt, E. The effects of temperature and drought on autumnal senescence and leaf shed in apple under warm, east mediterranean climate. Trees-Struct. Funct. 28, 879-890 (2014).

[15] Delledonne, M., Zeier, J., Marocco, A. & Lamb, C. Signal interactions between nitric oxide and reactive oxygen intermediates in the plant hypersensitive disease resistance response. Proc Natl Acad Sci USA 98, 13454-13459 (2001).

[16] Wang, Y., Lin, A., Loake, G. J. & Chu, C. H₂O₂-induced leaf cell death and the crosstalk of reactive nitric/oxygen species . J. Integr. Plant Biol. 55, 202-209 (2013).

[17] Estornell, L. H., Agustí, J., Merelo, P., Talón, M. & Tadeo, F. R. Elucidating mechanisms underlying organ abscission. Plant Sci. 199, 48-60 (2013).

[18] Liu, W. W., Kim, H. J., Chen, H. B., Lu, X. Y. & Zhou, B. Y. Identification of MV-generated ROS responsive EST clones in floral buds of Litchi chinensis Sonn. . Plant Cell Rep. 32, 1361-1372 (2013).

[19] Lu, X. et al. De novo transcriptome assembly for rudimentary leaves in Litchi chinesis Sonn. and identification of differentially expressed genes in response to reactive oxygen species . BMC. Genom. 15, 805-819 (2014).

[20] Liu, W. W. et al. Identification of nitric oxide responsive genes in the floral buds of Litchi chinensis . Biol. Plant. 59, 115-122 (2015).

[21] Li, J. Y. et al. The effects of molecular hydrogen and suberoylanilide hydroxamic acid on paraquat-induced production of reactive oxygen species and TNF-alpha in macrophages. Information 39, 1990-1996 (2016).

[22] Jimenez-Quesada, M. J. et al. Generation of nitric oxide by olive (Olea europaea L.) pollen during in vitro germination and assessment of the S-nitroso- and nitro-proteomes by computational predictive methods . Nitric Oxide 68, 23-37 (2017).

[23] Yang, H., Lu, X., Chen, H., Wang, C. & Zhou, B. Low temperature-induced leaf senescence and the expression of senescence-related genes in the panicles of Litchi chinensis . Biol. Plant. 61, 315-322 (2017).

[24] Dolezel, J., Greilhuber, J. & Suda, J. Estimation of nuclear DNA content in plants using flow cytometry. Nat. Protoc. 2, 2233-2244 (2007).

[25] Uheda, E., Kitoh, S. & Shiomi, N. Response of six Azolla species to transient high-temperature stress . Aquat. Bot. 64, 87-92 (1999).

[26] Uheda, E. & Nakamura, S. Abscission of Azolla branches induced by ethylene and sodium azide . Plant Cell Physiol. 41, 1365-1372 (2000).

[27] Roberts, J. A., Elliott, K. A. & Gonzalez-Carranza, Z. H. Abscission, dehiscence, and other cell separation processes. Annu. Rev. Plant Biol. 53, 131-158 (2002).

[28] Roberts, J. A., Schindler, C. B. & Tucker, G. A. Ethylene-promoted tomato flower abscission and the possible involvement of an inhibitor. Planta 160, 159-163 (1984).

[29] Kou, L. L. The Anatomical Study on Pedicel Abscission Zone Structure Development of Flower and Fruitlet in Litchi. Master thesis, South China Agricultural University, College of Horticulture (2012).

[30] Li, F. et al. Effect of cadmium stress on the growth, antioxidative enzymes and lipid peroxidation in two Kenaf (Hibiscus cannabinus L.) plant seedlings . J. Integr. Agric. 12, 610-620 (2013).

[31] Huang, W. et al. Reactive oxygen species burst induced by aluminum stress triggers mitochondria-dependent programmed cell death in peanut root tip cells. Plant. Physiol. Biochem. 82, 76-84 (2014).

[32] van Doorn, W. G. et al. Morphological classification of plant cell deaths. Cell Death Differ. 18, 1241-1246 (2011).

[33] Riccardi, C. & Nicoletti, I. Analysis of apoptosis by propidium iodide staining and flow cytometry. Nat. Protoc. 1, 1458-1461 (2006).

[34] Nicoletti, I., Migliorati, G., Pagliacci, M. C., Grignani, F. & Riccardi, C. A rapid and simple method for measuring thymocyte apoptosis by propidium iodide staining and flow cytometry. J. Immunol. Methods 139, 271-279 (1991).

[35] Darzynkiewicz, Z. et al. Features of apoptotic cells measured by flow cytometry. Cytometry 13, 759-808 (1992).

[36] Wang, G., Zhang, Z., Kong, D., Liu, Q. & Zhao, G. Programmed cell death is responsible for replaceable bud senescence in chestnut (Castanea mollissima BL.) . Plant Cell Rep. 31, 1603-1610 (2012).

[37] Yang, L. et al. Exogenous trehalose largely alleviates ionic unbalance, ROS burst, and PCD occurrence induced by high salinity in Arabidopsis seedlings . Front. Plant Sci. 5, 570 (2014).

[38] Reape, T. J. & McCabe, P. F. Apoptotic-like regulation of programmed cell death in plants. Apoptosis 15, 249-256 (2010).

[39] Woltering, E. J. Death proteases: alive and kicking. Trends Plant Sci. 15, 185-188 (2010).

[40] Grudkowska, M. & Zagdańska, B. Multifunctional role of plant cysteine proteinases. Acta Biochim. Pol. 51, 609-624 (2004).

[41] Van Breusegem, F. & Dat, J. F. Reactive oxygen species in plant cell death. Plant Physiol. 141, 384-390 (2006).

[42] Torres, M. A. & Dangl, J. L. Functions of the respiratory burst oxidase in biotic interactions, abiotic stress and development. Curr. Opin. Plant Biol. 8, 397-403 (2005).