Characterisation of proteins from date palm sap (Phoenix dactylifera L.) by a proteomic approach

A Review on Digestive System of Rhynchophorus ferrugineus as Potential Target to Develop Control Strategies

Rhynchophorus ferrugineus, commonly known as red palm weevil (RPW), is a high-risk insect pest that has become a threat to many important palm species. There are several dominant factors that lead to the successful infestation of RPW, including its stealthy lifestyle, highly chitinized mouthpart, and high fecundity rate. Due to that, millions of dollars of losses have been suffered by many countries invaded by RPW. Several methods have been designed to control its invasion, including the usage of insecticides, but many cause resistance and environmental pollution. Therefore, an environmentally friendly insecticide that targets specific systems or pathways in RPW is urgently needed. One of the potential targets is the digestive system of RPW, as it is the major interface between the insect and its plant host. The related knowledge of RPW's digestive system, such as the anatomy, microflora, transcriptomic analysis, and proteomic analysis, is important to understand its effects on RPW's survival. Several data from different omics regarding the digestive systems of RPW have been published in separate reports. Some of the potential targets have been reported to be inhibited by certain potential insecticides, while other targets have not yet been tested with any inhibitors. Hence, this review may lead to a better understanding on managing infestations of RPW using the system biology approach for its digestive system.

Efficacy of Bacillus subtilis (Ehrenberg1835) Cohn1872, in suppressing Fusarium oxysporum Schlecht. emend. Snyder & Hansen, the causal agent of root rot of date palm offshoots (Phoenix dactylifera L.) in Iraq

Date palm root rot disease is one of the most important diseases of date palms and offshoots. It is caused by many soil-borne pathogenic fungi. Pathogenicity assays of the isolated fungi showed that the major causative agents of root rot disease in date palm plantlets were Fusarium oxysporum Schlecht. emend. Snyder & Hansen, F. proliferatum (Matsush.) Nirenberg ex Gerlach & Nirenberg S1, F. proliferatum S2, Gibberella fujikuroi (Sawada) Wollenw., and Rhizoctonia solani J.G. Kühn. The most virulent fungus was F. oxysporum with a severity index of 82.16 % of root rot, while R. solani was the least harmful with a disease severity rate of 12.42 %. In laboratory tests, Bacillus subtilis reduced the radial mycelial growth of F. oxysporum on PDA medium by 86.6 %. The application of B. subtilis in combination with F. oxysporum substantially inhibited the severity of root rot disease relative to plantlets treated with only F. oxysporum. In addition, B. subtilis application in the presence or absence of F. oxysporum improved the plant physiology of plantlets, including total chlorophyll, total carotenoid, antioxidant enzyme levels (catalase and peroxidase), and total proline content.

Identification of Proteins Modulated in the Date Palm Stem Infested with Red Palm Weevil (Rhynchophorus ferrugineus Oliv.) Using Two Dimensional Differential Gel Electrophoresis and Mass Spectrometry

A state of the art proteomic methodology using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI TOF) has been employed to characterize peptides modulated in the date palm stem subsequent to infestation with red palm weevil (RPW). Our analyses revealed 32 differentially expressed peptides associated with RPW infestation in date palm stem. To identify RPW infestation associated peptides (I), artificially wounded plants (W) were used as additional control beside uninfested plants, a conventional control (C). A constant unique pattern of differential expression in infested (I), wounded (W) stem samples compared to control (C) was observed. The upregulated proteins showed relative fold intensity in order of I > W and downregulated spots trend as W > I, a quite interesting pattern. This study also reveals that artificially wounding of date palm stem affects almost the same proteins as infestation; however, relative intensity is quite lower than in infested samples both in up and downregulated spots. All 32 differentially expressed spots were subjected to MALDI-TOF analysis for their identification and we were able to match 21 proteins in the already existing databases. Relatively significant modulated expression pattern of a number of peptides in infested plants predicts the possibility of developing a quick and reliable molecular methodology for detecting plants infested with date palm.

Challenges in proteome analyses of tropical plants

Genome sequencing of various organisms allow global analysis of gene expression, providing numerous clues on the biological function and involvement in the biological processes studied. Proteomics is a branch of molecular biology and biotechnology that has undergone considerable development in the post-genomic era. Despite the recent significant advancements in proteomics techniques, still there is much to be improved. Due to peculiarities to the plant kingdom, proteomics approaches require adaptations, so as to improve efficiency and accuracy of results in plants. Data generated by proteomics can substantially contribute to the understanding and monitoring of plant physiological events and development of biotechnological strategies. Especially for tropical species, challenges are even greater, in the light of the abundance of secondary metabolites, as well as of the lack of complete genome sequences. This review discusses current topics in proteomics concerning challenges and perspectives, with emphasis on the proteomics of tropical plant species.