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SlDEAD31, a Putative DEAD-Box RNA Helicase Gene, Regulates Salt and Drought Tolerance and Stress-Related Genes in Tomato.

Zhu M, Chen G, Dong T, Wang L, Zhang J, Zhao Z, Hu Z - PLoS ONE (2015)

Bottom Line: Expression analysis indicated that SlDEAD30 was highly expressed in roots and mature leaves, while SlDEAD31 was constantly expressed in various tissues.In stress assays, transgenic tomato plants overexpressing SlDEAD31 exhibited dramatically enhanced salt tolerance and slightly improved drought resistance, which were simultaneously demonstrated by significantly enhanced expression of multiple biotic and abiotic stress-related genes, higher survival rate, relative water content (RWC) and chlorophyll content, and lower water loss rate and malondialdehyde (MDA) production compared to wild-type plants.Collectively, these results provide a preliminary characterization of SlDEAD30 and SlDEAD31 genes in tomato, and suggest that stress-responsive SlDEAD31 is essential for salt and drought tolerance and stress-related gene regulation in plants.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People's Republic of China.

ABSTRACT
The DEAD-box RNA helicases are involved in almost every aspect of RNA metabolism, associated with diverse cellular functions including plant growth and development, and their importance in response to biotic and abiotic stresses is only beginning to emerge. However, none of DEAD-box genes was well characterized in tomato so far. In this study, we reported on the identification and characterization of two putative DEAD-box RNA helicase genes, SlDEAD30 and SlDEAD31 from tomato, which were classified into stress-related DEAD-box proteins by phylogenetic analysis. Expression analysis indicated that SlDEAD30 was highly expressed in roots and mature leaves, while SlDEAD31 was constantly expressed in various tissues. Furthermore, the expression of both genes was induced mainly in roots under NaCl stress, and SlDEAD31 mRNA was also increased by heat, cold, and dehydration. In stress assays, transgenic tomato plants overexpressing SlDEAD31 exhibited dramatically enhanced salt tolerance and slightly improved drought resistance, which were simultaneously demonstrated by significantly enhanced expression of multiple biotic and abiotic stress-related genes, higher survival rate, relative water content (RWC) and chlorophyll content, and lower water loss rate and malondialdehyde (MDA) production compared to wild-type plants. Collectively, these results provide a preliminary characterization of SlDEAD30 and SlDEAD31 genes in tomato, and suggest that stress-responsive SlDEAD31 is essential for salt and drought tolerance and stress-related gene regulation in plants.

No MeSH data available.


Related in: MedlinePlus

The relative expression levels of biotic and abiotic stress-related genes of WT and SlDEAD31-overexpressing plants under normal and salt stress conditions.8-week-old plants were irrigated with water containing 400 mm NaCl (200 mL) from the bottoms of the pots, then root samples were harvested after 24 and 48 h. Seedlings harvested before the salt stress were used as controls. Bars represent mean relative expression values ± SE (n = 3). Asterisks indicate a significant difference (P<0.05) between WT and transgenic plants.
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pone.0133849.g007: The relative expression levels of biotic and abiotic stress-related genes of WT and SlDEAD31-overexpressing plants under normal and salt stress conditions.8-week-old plants were irrigated with water containing 400 mm NaCl (200 mL) from the bottoms of the pots, then root samples were harvested after 24 and 48 h. Seedlings harvested before the salt stress were used as controls. Bars represent mean relative expression values ± SE (n = 3). Asterisks indicate a significant difference (P<0.05) between WT and transgenic plants.

Mentions: To gain further information concerning the increased salt tolerance phenotype observed in SlDEAD31-overexpressing tomato plants, transcripts of previously reported stress-related genes were utilized for comparative analysis between WT and transgenic tomato roots under normal and salt-stressed conditions. The key ascorbic acid (AsA) synthetase gene GME2 [30]; two catalase (CAT) genes, Cat1 and Cat2 [31]; an ascorbate peroxidase (APX) gene, APX2 [32]; an ethylene-responsive LEA gene (ER5) [33]; the ethylene-responsive factor ERF1 [34], and two pathogenesis-related (PR) genes, PR1 and PR5 [35] were selected (Fig 7). Based on the reported literature, these stress tolerance genes are involved in the regulation of biotic and abiotic stress responses (such as PR1, PR5, ER5, and ERF1), production of osmolytes (such as GME2), detoxification and redox homeostasis (such as Cat1, Cat2, and APX2). Quantitative RT-PCR analysis showed that the transcripts of Cat1, ERF1, ER5, PR1, and PR5 were significantly elevated in almost all the overexpression lines under both normal and salt-stressed conditions, although the fold changes showed some variation for some genes among the three transgenic lines (Fig 7). Relatively higher expression levels of Cat2, APX2, and GME2 were detected mainly under normal conditions and at 24 h following salt stress in overexpression lines. The transcripts of these stress-related genes were also analyzed in the leaves of WT and transgenic plants, the results showed that their induction levels were less significant than in roots, as expected (taking into account that the expression of SlDEAD31 was only induced in roots by NaCl stress, Fig 4D, S4 Fig).


SlDEAD31, a Putative DEAD-Box RNA Helicase Gene, Regulates Salt and Drought Tolerance and Stress-Related Genes in Tomato.

Zhu M, Chen G, Dong T, Wang L, Zhang J, Zhao Z, Hu Z - PLoS ONE (2015)

The relative expression levels of biotic and abiotic stress-related genes of WT and SlDEAD31-overexpressing plants under normal and salt stress conditions.8-week-old plants were irrigated with water containing 400 mm NaCl (200 mL) from the bottoms of the pots, then root samples were harvested after 24 and 48 h. Seedlings harvested before the salt stress were used as controls. Bars represent mean relative expression values ± SE (n = 3). Asterisks indicate a significant difference (P<0.05) between WT and transgenic plants.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4524616&req=5

pone.0133849.g007: The relative expression levels of biotic and abiotic stress-related genes of WT and SlDEAD31-overexpressing plants under normal and salt stress conditions.8-week-old plants were irrigated with water containing 400 mm NaCl (200 mL) from the bottoms of the pots, then root samples were harvested after 24 and 48 h. Seedlings harvested before the salt stress were used as controls. Bars represent mean relative expression values ± SE (n = 3). Asterisks indicate a significant difference (P<0.05) between WT and transgenic plants.
Mentions: To gain further information concerning the increased salt tolerance phenotype observed in SlDEAD31-overexpressing tomato plants, transcripts of previously reported stress-related genes were utilized for comparative analysis between WT and transgenic tomato roots under normal and salt-stressed conditions. The key ascorbic acid (AsA) synthetase gene GME2 [30]; two catalase (CAT) genes, Cat1 and Cat2 [31]; an ascorbate peroxidase (APX) gene, APX2 [32]; an ethylene-responsive LEA gene (ER5) [33]; the ethylene-responsive factor ERF1 [34], and two pathogenesis-related (PR) genes, PR1 and PR5 [35] were selected (Fig 7). Based on the reported literature, these stress tolerance genes are involved in the regulation of biotic and abiotic stress responses (such as PR1, PR5, ER5, and ERF1), production of osmolytes (such as GME2), detoxification and redox homeostasis (such as Cat1, Cat2, and APX2). Quantitative RT-PCR analysis showed that the transcripts of Cat1, ERF1, ER5, PR1, and PR5 were significantly elevated in almost all the overexpression lines under both normal and salt-stressed conditions, although the fold changes showed some variation for some genes among the three transgenic lines (Fig 7). Relatively higher expression levels of Cat2, APX2, and GME2 were detected mainly under normal conditions and at 24 h following salt stress in overexpression lines. The transcripts of these stress-related genes were also analyzed in the leaves of WT and transgenic plants, the results showed that their induction levels were less significant than in roots, as expected (taking into account that the expression of SlDEAD31 was only induced in roots by NaCl stress, Fig 4D, S4 Fig).

Bottom Line: Expression analysis indicated that SlDEAD30 was highly expressed in roots and mature leaves, while SlDEAD31 was constantly expressed in various tissues.In stress assays, transgenic tomato plants overexpressing SlDEAD31 exhibited dramatically enhanced salt tolerance and slightly improved drought resistance, which were simultaneously demonstrated by significantly enhanced expression of multiple biotic and abiotic stress-related genes, higher survival rate, relative water content (RWC) and chlorophyll content, and lower water loss rate and malondialdehyde (MDA) production compared to wild-type plants.Collectively, these results provide a preliminary characterization of SlDEAD30 and SlDEAD31 genes in tomato, and suggest that stress-responsive SlDEAD31 is essential for salt and drought tolerance and stress-related gene regulation in plants.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, People's Republic of China.

ABSTRACT
The DEAD-box RNA helicases are involved in almost every aspect of RNA metabolism, associated with diverse cellular functions including plant growth and development, and their importance in response to biotic and abiotic stresses is only beginning to emerge. However, none of DEAD-box genes was well characterized in tomato so far. In this study, we reported on the identification and characterization of two putative DEAD-box RNA helicase genes, SlDEAD30 and SlDEAD31 from tomato, which were classified into stress-related DEAD-box proteins by phylogenetic analysis. Expression analysis indicated that SlDEAD30 was highly expressed in roots and mature leaves, while SlDEAD31 was constantly expressed in various tissues. Furthermore, the expression of both genes was induced mainly in roots under NaCl stress, and SlDEAD31 mRNA was also increased by heat, cold, and dehydration. In stress assays, transgenic tomato plants overexpressing SlDEAD31 exhibited dramatically enhanced salt tolerance and slightly improved drought resistance, which were simultaneously demonstrated by significantly enhanced expression of multiple biotic and abiotic stress-related genes, higher survival rate, relative water content (RWC) and chlorophyll content, and lower water loss rate and malondialdehyde (MDA) production compared to wild-type plants. Collectively, these results provide a preliminary characterization of SlDEAD30 and SlDEAD31 genes in tomato, and suggest that stress-responsive SlDEAD31 is essential for salt and drought tolerance and stress-related gene regulation in plants.

No MeSH data available.


Related in: MedlinePlus