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Genome duplication improves rice root resistance to salt stress.

Tu Y, Jiang A, Gan L, Hossain M, Zhang J, Peng B, Xiong Y, Song Z, Cai D, Xu W, Zhang J, He Y - Rice (N Y) (2014)

Bottom Line: We found that tetraploid rice showed less root growth inhibition, accumulated higher proline content and lower MDA content, and exhibited a higher frequency of normal epidermal cells than diploid rice.Furthermore, Na(+) in tetraploid rice roots significantly decreased while root tip H(+) efflux in tetraploid rice significantly increased.Our results suggest that genome duplication improves root resistance to salt stress, and that enhanced proton transport to the root surface may play a role in reducing Na(+) entrance into the roots.

View Article: PubMed Central - HTML - PubMed

Affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei University, Wuhan 430062, P.R. China.

ABSTRACT

Background: Salinity is a stressful environmental factor that limits the productivity of crop plants, and roots form the major interface between plants and various abiotic stresses. Rice is a salt-sensitive crop and its polyploid shows advantages in terms of stress resistance. The objective of this study was to investigate the effects of genome duplication on rice root resistance to salt stress.

Results: Both diploid rice (HN2026-2x and Nipponbare-2x) and their corresponding tetraploid rice (HN2026-4x and Nipponbare-4x) were cultured in half-strength Murashige and Skoog medium with 150 mM NaCl for 3 and 5 days. Accumulations of proline, soluble sugar, malondialdehyde (MDA), Na(+) content, H(+) (proton) flux at root tips, and the microstructure and ultrastructure in rice roots were examined. We found that tetraploid rice showed less root growth inhibition, accumulated higher proline content and lower MDA content, and exhibited a higher frequency of normal epidermal cells than diploid rice. In addition, a protective gap appeared between the cortex and pericycle cells in tetraploid rice. Next, ultrastructural analysis showed that genome duplication improved membrane, organelle, and nuclei stability. Furthermore, Na(+) in tetraploid rice roots significantly decreased while root tip H(+) efflux in tetraploid rice significantly increased.

Conclusions: Our results suggest that genome duplication improves root resistance to salt stress, and that enhanced proton transport to the root surface may play a role in reducing Na(+) entrance into the roots.

No MeSH data available.


Amount of free proline in roots of diploid and tetraploid rice under salt stress. Data represent the mean ± SD (n = 30 × 3 independent biological replicates:all samples were tested in three independent experiments with each included thirty rice plants). Means followed by common letters are not significantly different at P = 0.05 using a protected least-significant difference.
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Figure 2: Amount of free proline in roots of diploid and tetraploid rice under salt stress. Data represent the mean ± SD (n = 30 × 3 independent biological replicates:all samples were tested in three independent experiments with each included thirty rice plants). Means followed by common letters are not significantly different at P = 0.05 using a protected least-significant difference.

Mentions: Free proline in roots of diploid and tetraploid rice subjected to 150 mM NaCl for 5 days was measured (Figure 2). The amount of free proline in tetraploid rice cultivars under salt stress varied greatly and increased compared to diploid cultivars. The amounts of free proline in HN2026-2x and Nipponbare-2x were 132.09 and 98.12 μg g–1, respectively. Free proline accumulation was highest in HN2026-4x (157.91 μg g–1) and reached 120.99 μg g–1 in Nipponbare-4x. However, the increase in free proline in Nipponbare-4x compared with Nipponbare-2x was 23.30%. In addition, the increase in HN2026-4x was 19.55%.


Genome duplication improves rice root resistance to salt stress.

Tu Y, Jiang A, Gan L, Hossain M, Zhang J, Peng B, Xiong Y, Song Z, Cai D, Xu W, Zhang J, He Y - Rice (N Y) (2014)

Amount of free proline in roots of diploid and tetraploid rice under salt stress. Data represent the mean ± SD (n = 30 × 3 independent biological replicates:all samples were tested in three independent experiments with each included thirty rice plants). Means followed by common letters are not significantly different at P = 0.05 using a protected least-significant difference.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4151024&req=5

Figure 2: Amount of free proline in roots of diploid and tetraploid rice under salt stress. Data represent the mean ± SD (n = 30 × 3 independent biological replicates:all samples were tested in three independent experiments with each included thirty rice plants). Means followed by common letters are not significantly different at P = 0.05 using a protected least-significant difference.
Mentions: Free proline in roots of diploid and tetraploid rice subjected to 150 mM NaCl for 5 days was measured (Figure 2). The amount of free proline in tetraploid rice cultivars under salt stress varied greatly and increased compared to diploid cultivars. The amounts of free proline in HN2026-2x and Nipponbare-2x were 132.09 and 98.12 μg g–1, respectively. Free proline accumulation was highest in HN2026-4x (157.91 μg g–1) and reached 120.99 μg g–1 in Nipponbare-4x. However, the increase in free proline in Nipponbare-4x compared with Nipponbare-2x was 23.30%. In addition, the increase in HN2026-4x was 19.55%.

Bottom Line: We found that tetraploid rice showed less root growth inhibition, accumulated higher proline content and lower MDA content, and exhibited a higher frequency of normal epidermal cells than diploid rice.Furthermore, Na(+) in tetraploid rice roots significantly decreased while root tip H(+) efflux in tetraploid rice significantly increased.Our results suggest that genome duplication improves root resistance to salt stress, and that enhanced proton transport to the root surface may play a role in reducing Na(+) entrance into the roots.

View Article: PubMed Central - HTML - PubMed

Affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei University, Wuhan 430062, P.R. China.

ABSTRACT

Background: Salinity is a stressful environmental factor that limits the productivity of crop plants, and roots form the major interface between plants and various abiotic stresses. Rice is a salt-sensitive crop and its polyploid shows advantages in terms of stress resistance. The objective of this study was to investigate the effects of genome duplication on rice root resistance to salt stress.

Results: Both diploid rice (HN2026-2x and Nipponbare-2x) and their corresponding tetraploid rice (HN2026-4x and Nipponbare-4x) were cultured in half-strength Murashige and Skoog medium with 150 mM NaCl for 3 and 5 days. Accumulations of proline, soluble sugar, malondialdehyde (MDA), Na(+) content, H(+) (proton) flux at root tips, and the microstructure and ultrastructure in rice roots were examined. We found that tetraploid rice showed less root growth inhibition, accumulated higher proline content and lower MDA content, and exhibited a higher frequency of normal epidermal cells than diploid rice. In addition, a protective gap appeared between the cortex and pericycle cells in tetraploid rice. Next, ultrastructural analysis showed that genome duplication improved membrane, organelle, and nuclei stability. Furthermore, Na(+) in tetraploid rice roots significantly decreased while root tip H(+) efflux in tetraploid rice significantly increased.

Conclusions: Our results suggest that genome duplication improves root resistance to salt stress, and that enhanced proton transport to the root surface may play a role in reducing Na(+) entrance into the roots.

No MeSH data available.