cDNA-AFLP analysis reveals the adaptive responses of citrus to long-term boron-toxicity

Abstract

BackgroundBoron (B)-toxicity is an important disorder in agricultural regions across the world. Seedlings of ‘Sour pummelo’ (Citrus grandis) and ‘Xuegan’ (Citrus sinensis) were fertigated every other day until drip with 10 μM (control) or 400 μM (B-toxic) H3BO3 in a complete nutrient solution for 15 weeks. The aims of this study were to elucidate the adaptive mechanisms of citrus plants to B-toxicity and to identify B-tolerant genes.ResultsB-toxicity-induced changes in seedlings growth, leaf CO2 assimilation, pigments, total soluble protein, malondialdehyde (MDA) and phosphorus were less pronounced in C. sinensis than in C. grandis. B concentration was higher in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. Here we successfully used cDNA-AFLP to isolate 67 up-regulated and 65 down-regulated transcript-derived fragments (TDFs) from B-toxic C. grandis leaves, whilst only 31 up-regulated and 37 down-regulated TDFs from B-toxic C. sinensis ones, demonstrating that gene expression is less affected in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. These differentially expressed TDFs were related to signal transduction, carbohydrate and energy metabolism, nucleic acid metabolism, protein and amino acid metabolism, lipid metabolism, cell wall and cytoskeleton modification, stress responses and cell transport. The higher B-tolerance of C. sinensis might be related to the findings that B-toxic C. sinensis leaves had higher expression levels of genes involved in photosynthesis, which might contribute to the higher photosyntheis and light utilization and less excess light energy, and in reactive oxygen species (ROS) scavenging compared to B-toxic C. grandis leaves, thus preventing them from photo-oxidative damage. In addition, B-toxicity-induced alteration in the expression levels of genes encoding inorganic pyrophosphatase 1, AT4G01850 and methionine synthase differed between the two species, which might play a role in the B-tolerance of C. sinensis.ConclusionsC. sinensis leaves could tolerate higher level of B than C. grandis ones, thus improving the B-tolerance of C. sinensis plants. Our findings reveal some novel mechanisms on the tolerance of plants to B-toxicity at the gene expression level.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0284-5) contains supplementary material, which is available to authorized users.

Long-term boron-deficiency-responsive genes revealed by cDNA-AFLP differ between Citrus sinensis roots and leaves

“…The expression of cytochrome P450s ( CytoP450s ) was increased in Vicia sativa seedlings when exposed to plant hormone methyl jasmonate (Pinot et al, 1998 ) and in B-toxic C. grandis leaves (Guo et al, 2014 ). Transgenic tobacco and potato plants over-expressing CytoP450 displayed increased monooxygenase activity and enhanced tolerance of oxidative stress after herbicide treatment (Gorinova et al, 2005 ).…”

Boron toxicity in higher plants: an update

“…For example, the capacity to bind ATP and NADPH (Cervilla et al 2009a) and limit the availability of energy and reduce power, respectively, which are necessary for carbohydrate synthesis in the light-independent reactions of the Calvin-Benson cycle. Therefore, changes in sugar content and partitioning (Roessner et al 2006;Papadakis et al 2018), as well as in carbon skeleton devoted to aminoacids, which are strictly interlinked (Guo et al 2014) can be observed as a response to B excess (Sang et al 2015;Ayvaz et al 2016). An imbalance of C/N ratio also promote phenomena of early senescence (Lo Piccolo et al 2018;Sotiras et al 2019) and this explains the enhancement of senescence-related hormones i.e.…”

Boron Toxicity Causes Multiple Effects on Malus domestica Pollen Tube Growth

“…Boron toxicity has been shown to affect several developmental or biochemical processes in plants ( Sakamoto et al, 2011 ), including inhibiting the formation of glutathione ( Ruiz et al, 2003 ) and tocopherol ( Keles et al, 2004 ), reducing root cell division ( Aquea et al, 2012 ), and shoot cell wall expansion ( Loomis and Durst, 1992 ), decreasing fruit number, size and weight, formatting reactive oxygen species(ROSs) ( Paull et al, 1992 ; Nable et al, 1997 ; Karabal et al, 2003 ; Cervilla et al, 2007 ), increasing oxidative damage ( Gunes et al, 2006 ; Molassiotis et al, 2006 ; Sotiropoulos et al, 2006 ), affecting the photosynthesis and antioxidant apparatus ( Landi et al, 2013 ), and leading to DNA damage ( Sakamoto et al, 2011 ). A cDNA-AFLP analysis revealed that long-term boron stress induced changes related to signal transduction, metabolism of carbohydrate, energy, nucleic acid, protein, amino acid and lipid, cell wall and cytoskeleton modification, stress responses, and cell transport in Citrus grandis and Citrus sinensis ( Guo et al, 2014 ). Furthermore, several genes involved in plant tolerance to boron stress have been identified, including Arabidopsis thaliana BOR4 and TIP5;1 ( Miwa et al, 2007 ; Pang et al, 2010 ), barley ( Hordeu mvulgare ) Bot1 ( Sutton et al, 2007 ), wheat and barley HvBOR2 ( Reid, 2007 ), and citrus ( Citrus macrophylla ) CmBOR1 ( Cañon et al, 2013 ).…”