Document Details

Document Type : Thesis 
Document Title :
Detection of gene regulation and metabolic pathways under drought and heat stresses in senna (Cassia angustifolia)
التعرف على التنظيم الجيني والمسارات الأيضية تحت ظروف أجهادي الجفاف والحرارة في نبات السنا
 
Subject : Faculty of Science 
Document Language : Arabic 
Abstract : This study aimed the detection the molecular dynamics of drought stress tolerance in the wild plant species senna (Cassia angustifolia Vahl.) that has important pharmaceutical applications as mainly being used as a laxative. We have studied RNA-Seq datasets produced by next-generation sequencing (NGS) of leaf before (day 1) and after (day 2) watering at three time points (post-dawn, midday and post-dusk). Raw data were de novo assembled to study the differential response due to watering. Hierarchical cluster analysis of gene expression showed that transcriptomes within any given time point were closely related, except for those of the midday that were completely separated due to watering. GO classification indicated that several GO terms participate in processes related to tolerance under abiotic stress. Cluster analysis indicated the occurrence of several expression patterns that were light-, heat-, dawn- and night-specific. Differential watering responses were detected only at midday. A large number of drought-related genes and transcription factor families including NAC, MYC2 and CCCH zinc finger family of TFs (namely TZF) that are major player in plant growth and responses to stresses such as drought and salinity. KEGG analysis for genes whose differential expression in midday between the two days was ≥5 FC resulted in a number of enzymes that were found repressed due to watering, thus likely participate in the molecular mechanisms utilized by the organism to adapt to the long-lasting drought stress. The recovered regulated metabolites and enzymes included abscisic acid (ABA) receptor PYL4 and PYL9, auxin response factors (ARF) 5 and 15, Aux/IAA proteins IAA7 and IAA14, indole-3-pyruvate (or flavin) monooxygenase, phosphoinositide phosphatase SAC1 and SAC6, pre-mRNA splicing factors 8, 8A, 19, 40A and ISY1, and serine/arginine-rich splicing regulators SCL33, RS31 and RS34. The two pathways tryptophan metabolism and plant hormone signal transduction likely crosstalk in senna (C. angustifolia) towards the maintenance of normal growth under adverse condition. Many other regulated metabolites and proteins in senna (C. angustifolia) including brassinosteroid, heat shock protein 95s, ATPase, several protein kinases such as mitogen-activated protein kinase (MAPK) and cytochrome c oxidase. Other enzymes include phospholipase C2 and allene oxide cyclase as well as isochorismate pathway were also regulated in senna (C. angustifolia). In conclusion, we have scoped the light on the possible molecular mechanism underlying drought stress tolerance in the wild plant senna (C. angustifolia) that can be utilized in further plant breeding programs. 
Supervisor : Prof. Dr. Ahmed Bahieldin 
Thesis Type : Doctorate Thesis 
Publishing Year : 1440 AH
2019 AD 
Co-Supervisor : Prof. Dr. Hassan Said Alzahrani 
Added Date : Wednesday, August 21, 2019 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
نادية بخيت السلميal-Sulami, Nadiah BakheetResearcherDoctorate 

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