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Expression profiling of abiotic stress-inducible genes in response to multiple stresses in rice (Oryza sativa L.) varieties with contrasting level of stress tolerance.

Basu S, Roychoudhury A - Biomed Res Int (2014)

Bottom Line: Heat map data also showed differential transcript abundance in the three varieties, correlating the observation with transcript profiling.In silico analysis of the upstream regions of all the genes represented the existence of conserved sequence motifs in single or multiple copies that are indispensable to abiotic stress response.The present work will pave the way in future to select gene(s) for overexpression, so as to generate broad spectrum resistance to multiple stresses simultaneously.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop, Soil, and Environmental Sciences, University of Arkansas, 115 Plant Sciences Building, Fayetteville, AR 72701, USA.

ABSTRACT
The present study considered transcriptional profiles and protein expression analyses from shoot and/or root tissues under three abiotic stress conditions, namely, salinity, dehydration, and cold, as well as following exogenous abscisic acid treatment, at different time points of stress exposure in three indica rice varieties, IR-29 (salt sensitive), Pokkali, and Nonabokra (both salt tolerant). The candidate genes chosen for expression studies were HKT-1, SOS-3, NHX-1, SAPK5, SAPK7, NAC-1, Rab16A, OSBZ8, DREBP2, CRT/DREBP, WRKY24, and WRKY71, along with the candidate proteins OSBZ8, SAMDC, and GST. Gene expression profile revealed considerable differences between the salt-sensitive and salt-tolerant rice varieties, as the expression in the latter was higher even at the constitutive level, whereas it was inducible only by corresponding stress signals in IR-29. Whether in roots or shoots, the transcriptional responses to different stressors peaked following 24 h of stress/ABA exposure, and the transcript levels enhanced gradually with the period of exposure. The generality of stress responses at the transcriptional level was therefore time dependent. Heat map data also showed differential transcript abundance in the three varieties, correlating the observation with transcript profiling. In silico analysis of the upstream regions of all the genes represented the existence of conserved sequence motifs in single or multiple copies that are indispensable to abiotic stress response. Overall, the transcriptome and proteome analysis undertaken in the present study indicated that genes/proteins conferring tolerance, belonging to different functional classes, were overrepresented, thus providing novel insight into the functional basis of multiple stress tolerance in indica rice varieties. The present work will pave the way in future to select gene(s) for overexpression, so as to generate broad spectrum resistance to multiple stresses simultaneously.

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Semiquantitative RT-PCR analysis showing differential gene expression in leaf tissues (a) and roots (b) of 12-day-old seedlings of IR-29 (salt sensitive), Pokkali, and Nonabokra (both salt tolerant) rice cultivars in response to salinity stress (200 mM NaCl); salt stress was imposed for 6/16/24 hours (in IR-29 and Pokkali) and for 6/24 hours (in Nonabokra) to detect transcript level in leaves, whereas for roots, the durations of stress treatment were 24 hours (in IR-29 and Pokkali) and 6/24 hours (in Nonabokra); the expression of each gene was compared relative to its expression in control C (untreated) sample (0 h).
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fig2: Semiquantitative RT-PCR analysis showing differential gene expression in leaf tissues (a) and roots (b) of 12-day-old seedlings of IR-29 (salt sensitive), Pokkali, and Nonabokra (both salt tolerant) rice cultivars in response to salinity stress (200 mM NaCl); salt stress was imposed for 6/16/24 hours (in IR-29 and Pokkali) and for 6/24 hours (in Nonabokra) to detect transcript level in leaves, whereas for roots, the durations of stress treatment were 24 hours (in IR-29 and Pokkali) and 6/24 hours (in Nonabokra); the expression of each gene was compared relative to its expression in control C (untreated) sample (0 h).

Mentions: With respect to salinity stress, the genes HKT-1, SOS-3, SAPK5, and OSBZ8 showed better induction in expression in the leaves of all the three varieties, with increase in duration of stress, the maximum induction being recorded at 24 h of NaCl treatment. With the exception of CRT/DREBP, the expression of all the genes in leaves was recorded the maximum in Nonabokra, with all the genes showing constitutive expression. Though the tolerant cultivar Pokkali also showed gene expression at the constitutive level, the induction was considerably high in the susceptible variety IR-29, especially for the genes like HKT-1, SAPK5, Rab16A, and OSBZ8 (Figure 2(a)). In roots, the genes HKT-1, SAPK5, and DREBP2 showed high level of expression with salinity stress in all the three varieties. Of the three varieties, Nonabokra again showed the highest level of expression of all the genes tested. The induction in HKT-1, SAPK5, Rab16A, and DREBP2 was recorded especially in the salt-sensitive cultivar (Figure 2(b)). The MADS6 gene was unaffected by stress treatment, though the level of the transcript was detected higher in the leaves of the tolerant varieties Pokkali and Nonabokra (Figure 2(a)).


Expression profiling of abiotic stress-inducible genes in response to multiple stresses in rice (Oryza sativa L.) varieties with contrasting level of stress tolerance.

Basu S, Roychoudhury A - Biomed Res Int (2014)

Semiquantitative RT-PCR analysis showing differential gene expression in leaf tissues (a) and roots (b) of 12-day-old seedlings of IR-29 (salt sensitive), Pokkali, and Nonabokra (both salt tolerant) rice cultivars in response to salinity stress (200 mM NaCl); salt stress was imposed for 6/16/24 hours (in IR-29 and Pokkali) and for 6/24 hours (in Nonabokra) to detect transcript level in leaves, whereas for roots, the durations of stress treatment were 24 hours (in IR-29 and Pokkali) and 6/24 hours (in Nonabokra); the expression of each gene was compared relative to its expression in control C (untreated) sample (0 h).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109260&req=5

fig2: Semiquantitative RT-PCR analysis showing differential gene expression in leaf tissues (a) and roots (b) of 12-day-old seedlings of IR-29 (salt sensitive), Pokkali, and Nonabokra (both salt tolerant) rice cultivars in response to salinity stress (200 mM NaCl); salt stress was imposed for 6/16/24 hours (in IR-29 and Pokkali) and for 6/24 hours (in Nonabokra) to detect transcript level in leaves, whereas for roots, the durations of stress treatment were 24 hours (in IR-29 and Pokkali) and 6/24 hours (in Nonabokra); the expression of each gene was compared relative to its expression in control C (untreated) sample (0 h).
Mentions: With respect to salinity stress, the genes HKT-1, SOS-3, SAPK5, and OSBZ8 showed better induction in expression in the leaves of all the three varieties, with increase in duration of stress, the maximum induction being recorded at 24 h of NaCl treatment. With the exception of CRT/DREBP, the expression of all the genes in leaves was recorded the maximum in Nonabokra, with all the genes showing constitutive expression. Though the tolerant cultivar Pokkali also showed gene expression at the constitutive level, the induction was considerably high in the susceptible variety IR-29, especially for the genes like HKT-1, SAPK5, Rab16A, and OSBZ8 (Figure 2(a)). In roots, the genes HKT-1, SAPK5, and DREBP2 showed high level of expression with salinity stress in all the three varieties. Of the three varieties, Nonabokra again showed the highest level of expression of all the genes tested. The induction in HKT-1, SAPK5, Rab16A, and DREBP2 was recorded especially in the salt-sensitive cultivar (Figure 2(b)). The MADS6 gene was unaffected by stress treatment, though the level of the transcript was detected higher in the leaves of the tolerant varieties Pokkali and Nonabokra (Figure 2(a)).

Bottom Line: Heat map data also showed differential transcript abundance in the three varieties, correlating the observation with transcript profiling.In silico analysis of the upstream regions of all the genes represented the existence of conserved sequence motifs in single or multiple copies that are indispensable to abiotic stress response.The present work will pave the way in future to select gene(s) for overexpression, so as to generate broad spectrum resistance to multiple stresses simultaneously.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop, Soil, and Environmental Sciences, University of Arkansas, 115 Plant Sciences Building, Fayetteville, AR 72701, USA.

ABSTRACT
The present study considered transcriptional profiles and protein expression analyses from shoot and/or root tissues under three abiotic stress conditions, namely, salinity, dehydration, and cold, as well as following exogenous abscisic acid treatment, at different time points of stress exposure in three indica rice varieties, IR-29 (salt sensitive), Pokkali, and Nonabokra (both salt tolerant). The candidate genes chosen for expression studies were HKT-1, SOS-3, NHX-1, SAPK5, SAPK7, NAC-1, Rab16A, OSBZ8, DREBP2, CRT/DREBP, WRKY24, and WRKY71, along with the candidate proteins OSBZ8, SAMDC, and GST. Gene expression profile revealed considerable differences between the salt-sensitive and salt-tolerant rice varieties, as the expression in the latter was higher even at the constitutive level, whereas it was inducible only by corresponding stress signals in IR-29. Whether in roots or shoots, the transcriptional responses to different stressors peaked following 24 h of stress/ABA exposure, and the transcript levels enhanced gradually with the period of exposure. The generality of stress responses at the transcriptional level was therefore time dependent. Heat map data also showed differential transcript abundance in the three varieties, correlating the observation with transcript profiling. In silico analysis of the upstream regions of all the genes represented the existence of conserved sequence motifs in single or multiple copies that are indispensable to abiotic stress response. Overall, the transcriptome and proteome analysis undertaken in the present study indicated that genes/proteins conferring tolerance, belonging to different functional classes, were overrepresented, thus providing novel insight into the functional basis of multiple stress tolerance in indica rice varieties. The present work will pave the way in future to select gene(s) for overexpression, so as to generate broad spectrum resistance to multiple stresses simultaneously.

Show MeSH
Related in: MedlinePlus