Dataset Information

Phosphorus application reduces aluminum toxicity in two Eucalyptus clones by increasing its accumulation in roots and decreasing its content in leaves.

ABSTRACT: Under acidic conditions, aluminum (Al) toxicity is an important factor limiting plant productivity; however, the application of phosphorus (P) might alleviate the toxic effects of Al. In this study, seedlings of two vegetatively propagated Eucalyptus clones, E. grandis × E. urophylla 'G9' and E. grandis × E. urophylla 'DH32-29'were subjected to six treatments (two levels of Al stress and three levels of P). Under excessive Al stress, root Al content was higher, whereas shoot and leaf Al contents were lower with P application than those without P application. Further, Al accumulation was higher in the roots, but lower in the shoots and leaves of G9 than in those of DH32-29. The secretion of organic acids was higher under Al stress than under no Al stress. Further, under Al stress, the roots of G9 secreted more organic acids than those of DH32-29. With an increase in P supply, Al-induced secretion of organic acids from roots decreased. Under Al stress, some enzymes, including PEPC, CS, and IDH, played important roles in organic acid biosynthesis and degradation. Thus, our results indicate that P can reduce Al toxicity via the fixation of elemental Al in roots and restriction of its transport to stems and leaves, although P application cannot promote the secretion of organic acid anions. Further, the higher Al-resistance of G9 might be attributed to the higher Al accumulation in and organic acid anion secretion from roots and the lower levels of Al in leaves.

SUBMITTER: Teng W

PROVIDER: S-EPMC5764327 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

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Phosphorus application reduces aluminum toxicity in two Eucalyptus clones by increasing its accumulation in roots and decreasing its content in leaves.

Teng Weichao W Kang Yachao Y Hou Wenjuan W Hu Houzhen H Luo Wenji W Wei Jie J Wang Linghui L Zhang Boyu B

PloS one 20180111 1

Under acidic conditions, aluminum (Al) toxicity is an important factor limiting plant productivity; however, the application of phosphorus (P) might alleviate the toxic effects of Al. In this study, seedlings of two vegetatively propagated Eucalyptus clones, E. grandis × E. urophylla 'G9' and E. grandis × E. urophylla 'DH32-29'were subjected to six treatments (two levels of Al stress and three levels of P). Under excessive Al stress, root Al content was higher, whereas shoot and leaf Al contents ...[more]

PMID: 29324770

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Project description:Aluminum (Al) toxicity is a major factor limiting crop yields on acid soils. In maize, Al tolerance is a complex phenomenon involving multiple genes and physiological mechanisms yet uncharacterized. To begin elucidating the molecular basis of maize Al toxicity and tolerance, we performed a detailed temporal analysis of root gene expression under Al stress using microarrays with an Al-tolerant and an Al-sensitive maize genotype. Seedlings of both genotypes were grown in hydroponics in a full nutrient solution containing 39uM of free Al3+ activity. Root samples were collected at 'time zero', and after 2, 6 and 24 hours of treatment. Time course experiment with 0h, 2h, 6h and 24 hours of Al treatment in two maize genotypes contrasting for Al tolerance. The experimental design used for the microarray study was of two interconnected loops, and utilized a total of 16 slide sets. Samples collected from each genotype at one time point were contrasted with the previous and subsequent time points in a loop (4 time points x 2 genotypes = 8 slide sets). Additionally, the loops were interconnected (with dye swap) so that the two genotypes were contrasted directly at each time point (4 time points x 2 replicates = 8 slide sets). The design was balanced for dye distribution throughout samples and biological replicates. Each sample was labeled twice with Cy3 and twice with Cy5; each biological replicate had four samples labeled with Cy3 and four samples labeled with Cy5. The Sample signal intensity values were log2 transformed and analyzed by two interconnected ANOVA mixed models using PROC MIXED in SAS (Jin et al., 2001; Wolfinger et al., 2001). The normalization ANOVA model yij = Âµ + Ai + Dj + (A x D)ij + eij was applied to account for experiment-wide sources of variation associated with array (Ai, degrees of freedom (df) = 15, random effect), dye (Dj, df = 1, fixed effect), and their interactions. The residuals (eij) were treated as normalized values and analyzed in the following ANOVA model (gene model), where effects were evaluated for each gene individually: rikl = Âµ + Ai + Gk + Tl + (G x T)kl + ekl. Gk is the kth genotype (i.e. C100-6 or L53; df = 1) and represents the effect of each genotype on the expression of every gene, Tl represents the lth treatment (i.e. 0, 2, 6 or 24 hours of Al treatment; df = 3), and (G x T)kl the interaction between genotype and treatment (df = 3). Array (Ai) was included as a random effect to control for spot effects (Jin et al., 2001). Least square means were calculated, and estimates of differential expression were calculated as the difference between least-square means for each of the terms in the model. ANOVA results linked below as Supplementary files.

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Dataset Information

Phosphorus application reduces aluminum toxicity in two Eucalyptus clones by increasing its accumulation in roots and decreasing its content in leaves.

Publications

Phosphorus application reduces aluminum toxicity in two Eucalyptus clones by increasing its accumulation in roots and decreasing its content in leaves.

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