Agarwood Induction: Current Developments and Future Perspectives

Agarwood is a resinous part of the non-timber Aquilaria tree, which is a highly valuable product for medicine and fragrance purposes. To protect the endangered Aquilaria species, mass plantation of Aquilaria trees has become a sustainable way in Asian countries to obtain the highly valuable agarwood. As only physiologically triggered Aquilaria tree can produce agarwood, effective induction methods are long sought in the agarwood industry. In this paper, we attempt to provide an overview for the past efforts toward the understanding of agarwood formation, the evolvement of induction methods and their further development prospects by integrating it with high-throughput omics approaches

Characterization and functional study of stress-associated protein in rice and arabidopsis

Environmental stress can hinder the growth and development of crops, thereby reducing productivity. Plants can adapt to changing environments through various morpho-physiological changes, transcriptome regulation, signaling, translational and post-translational modifications. Stress Associated Proteins (SAPs) have been shown to play a crucial role in plant adaptation to biotic and abiotic stressors. They are encoded by a family of genes that produce a zinc finger protein with A20 and/or AN1 domains at either their N or C-terminal ends. Therefore, this study focused on understanding the role of the Oryza sativa SAP gene family (OsSAPs) in response to drought and salinity stress. In-silico analysis revealed that most of the OsSAP family members were upregulated by stress; two highly inducible OsSAP genes were also upregulated in response to stress under a rice-specific background. To study gene function, an Arabidopsis transformation system was employed using three genotypes: Col-0 (wild type), overexpressed transgenic OsSAP8, and atsap2 T-DNA knockout mutant. Arabidopsis AtSAP2 gene, which is homologous to rice OsSAP8, was used as a comparison to the loss of function mutation in Arabidopsis. Morpho-physiological analysis showed that the atsap2 mutant displayed a sensitive phenotype to drought and salinity stress through low relative chlorophyll content and delayed inflorescence development and flowering as compared to Col-0 and transgenic OsSAP8. This suggests that the abolished atsap2 gene may contribute to reduced stress tolerance in plants. In contrast, transgenic OsSAP8 overexpression demonstrated tolerance to drought and salinity stress by maintaining relative chlorophyll content under both stress conditions, indirectly reflecting sustained photosynthetic machinery and stable photosynthetic rate. Further investigation, such as measuring the photosynthesis rate, is required to establish the correlation between chlorophyll data and photosynthesis activity

Transformasi Gen Proteolisis 6 (PRT6) berperantarakan Agrobacterium tumefaciens ke dalam kotiledon tomato kultivar Micro Tom

Gen Proteolisis 6 (PRT6) merupakan gen yang memainkan peranan penting dalam tapak jalan N-end rule dan berfungsi sebagai enzim E3 ligase. PRT6 berperanan dalam pengenalan protein sasaran bagi proses degradasi. Objektif utama kajian ini adalah untuk mentransformasi konstruk RNAi PRT6 ke dalam tomato berperantarakan Agrobacterium tumefaciens. Ini bertujuan untuk memahami peranan tapak jalan N-end rule semasa proses pemasakan buah. Beberapa faktor yang memberi kesan kepada transformasi seperti masa ko-penanaman dan juga kepekatan antibiotik yang digunakan telah dioptimumkan. Keputusan kajian menunjukkan pengeraman kotiledon selama 48 jam pada medium ko-penanaman dapat meningkatkan penghasilan kalus sebanyak 61% manakala penggunaan 500 mg/L antibiotik karbenisilin dalam medium regenerasi pucuk dapat mengurangkan kontaminasi A. tumefaciens sehingga 5.2%. Selain itu, strain A. tumefaciens C58 merupakan strain A. tumefaciens yang paling sesuai digunakan sebagai perantara dalam kajian ini. Tindak balas berantai polimerase (PCR) telah dijalankan pada pucuk yang terhasil untuk mengesahkan integrasi fragmen PRT6 ke dalam genom tomato. Berdasarkan analisis PCR, kesemua tujuh pucuk putatif transgenik adalah merupakan transforman positif

Nitric oxide sensing in plants is mediated by proteolytic control of group VII ERF transcription factors

Nitric oxide (NO) is an important signaling compound in prokaryotes and eukaryotes. In plants, NO regulates critical developmental transitions and stress responses. Here, we identify a mechanism for NO sensing that coordinates responses throughout development based on targeted degradation of plant-specific transcriptional regulators, the group VII ethylene response factors (ERFs). We show that the N-end rule pathway of targeted proteolysis targets these proteins for destruction in the presence of NO, and we establish them as critical regulators of diverse NO-regulated processes, including seed germination, stomatal closure, and hypocotyl elongation. Furthermore, we define the molecular mechanism for NO control of germination and crosstalk with abscisic acid (ABA) signaling through ERF-regulated expression of ABSCISIC ACID INSENSITIVE5 (ABI5). Our work demonstrates how NO sensing is integrated across multiple physiological processes by direct modulation of transcription factor stability and identifies group VII ERFs as central hubs for the perception of gaseous signals in plants

RNA-seq data of Oryza sativa cultivar Kuku Belang under PEG treatment

Drought stress is the main abiotic factor affecting rice production. Rain-fed upland rice which is grown on unbounded fields and totally dependent on rainfall for moisture is more prone to drought stress compared to rice from other ecosystems. However, upland rice has adapted to this limited water condition, thus are more drought tolerant than rice from other ecosystems. We performed the first transcriptome sequencing of drought tolerant indica upland rice cultivar Kuku Belang to identify differentially expressed genes related to drought tolerance mechanism. Raw reads for non-treated and PEG-treated Oryza sativa subspecies indica cv. Kuku Belang were deposited in the NCBI SRA database with accession number SRP074520 (https://www.ncbi.nlm.nih.gov/sra?term=SRP074520)

Morpho-Physiological and Stress-Related Gene Expression of Rice Varieties in Response to Salinity Stress at Early Vegetative Stage

This study focuses on the growth and morpho-physiological responses of the Malaysian commercial variety MR219 rice to salinity stress during the early vegetative stages, specifically during germination and the five-leaf stage. For germination responses, MR219 seeds were grown for 10 days in different salt concentrations. Low salinity significantly improves seed germination and increases the total number of germinated seeds. However, higher salinity (160 mM NaCl) inhibits the germination of MR219 seeds and reduces the total number of germinated seeds by 93.3%. The effects of salinity on the five-leaf stage of MR219 were also determined and compared to the salinity-tolerant (Pokkali) and susceptible (IR64) varieties. There were significant reductions in the photosynthesis rate, transpiration rate, stomatal conductance, and leaf chlorophyll content by 28.1%, 58.6%, 81.1%, and 3.7%, respectively. These reductions could contribute to the significant decrease in growth parameters measured throughout the treatment period. Based on the principal component analysis (PCA) result, MR219 is more tolerant to salinity than IR64, but is less tolerant than Pokkali. Further investigation on stress-related gene expression suggests that significant changes in the transcript level of genes involved in gamma-aminobutyric acid (GABA) shunt, ion transport, and reactive oxygen species detoxification could be attributed to the adaptation and tolerance level of each variety to salinity stress

Morpho-Physiological and Stress-Related Gene Expression of Rice Varieties in Response to Salinity Stress at Early Vegetative Stage

This study focuses on the growth and morpho-physiological responses of the Malaysian commercial variety MR219 rice to salinity stress during the early vegetative stages, specifically during germination and the five-leaf stage. For germination responses, MR219 seeds were grown for 10 days in different salt concentrations. Low salinity significantly improves seed germination and increases the total number of germinated seeds. However, higher salinity (160 mM NaCl) inhibits the germination of MR219 seeds and reduces the total number of germinated seeds by 93.3%. The effects of salinity on the five-leaf stage of MR219 were also determined and compared to the salinity-tolerant (Pokkali) and susceptible (IR64) varieties. There were significant reductions in the photosynthesis rate, transpiration rate, stomatal conductance, and leaf chlorophyll content by 28.1%, 58.6%, 81.1%, and 3.7%, respectively. These reductions could contribute to the significant decrease in growth parameters measured throughout the treatment period. Based on the principal component analysis (PCA) result, MR219 is more tolerant to salinity than IR64, but is less tolerant than Pokkali. Further investigation on stress-related gene expression suggests that significant changes in the transcript level of genes involved in gamma-aminobutyric acid (GABA) shunt, ion transport, and reactive oxygen species detoxification could be attributed to the adaptation and tolerance level of each variety to salinity stress

The effect of MS media strength and cytokinin in the induction of shoots from shoot tip explants of Australian Finger Lime (Citrus australasica cv. Tasty Green)

The Australian Finger Lime (Citrus australasica) is a type of citrus from the Rutaceae family, endemic to the east coast of Australia. The finger lime, loaded with numerous vitamins and renders a unique taste, has also been backed by science to contain essential amounts of antioxidants that are beneficial for cell protection, immune response, cancer prevention, ageing, arthritis and prevention of kidney stones. Current propagation attempts still rely on conventional methods that are less efficient and resulted in the slow establishment of farms for finger lime especially for commercialization purposes. This study focuses on the induction of shoots from shoot tip explants using 6-Benzylaminopurine (BAP) and Kinetin. Aseptic explants were inoculated into Murashige and Skoog (MS) medium of full-strength and half-strength followed by full-strength MS media supplemented with different concentrations of BAP and Kinetin. Results obtained in this study showed no significant differences in terms of the number of axillary shoots produced between explants cultured in full and half-strength MS media. However, the highest number of shoots and increment in shoot length were obtained from MS media supplemented with 2.0 mg/L BAP with the values 1.80 ± 0.27 and 2.56 ± 0.36 cm, respectively. In conclusion, MS media supplemented with 2.0 mg/L BAP was found optimal in the induction of shoots and shoot elongation of C. australasica cv. Tasty Green

Effect of rice AUXIN BINDING PROTEIN57 (OsABP57) overexpression in response to flooding

This study reports the effects of Oryza sativa AUXIN BINDING PROTEIN57 (OsABP57) overexpression towards flooding in rice. OsABP57 was previously reported to activate plasma membrane H+ -ATPase. Earlier studies address the ability of transgenic OsABP57 overexpression in enduring drought and salinity stresses but none on the flooding. In this study, complete submergence analysis was carried out and several morphophysiological parameters were analyzed such as plant height, root architecture and relative chlorophyll content. Results showed that there are no differences between OsABP57 overexpression rice compared to MR219 control rice in terms of chlorophyll content and plant height after 1-3 weeks of flooding treatments. Root analysis, however, found that transgenic rice OsABP57 produced more adventitious roots compared to MR219 rice under normal condition, which may be due to the role of the gene that encodes for auxin binding protein. The semi-quantitative polymerase chain reaction (PCR) on Oryza sativa pyruvate decarboxylase (OsPDC) gene after two weeks of flooding treatment showed an increase of expression in OsABP57 transgenic compared to MR219. Overall, the overexpression of OsABP57 did not show any significant difference in terms of morphophysiological analysis between the transgenic line and MR219, yet, there is an increase of OsPDC gene in the transgenic background which may need further experimental analysis in the future to map the network between auxin and hypoxia core genes

Morpho-Physiology and Antioxidant Enzyme Activities of Transgenic Rice Plant Overexpressing ABP57 under Reproductive Stage Drought Condition

MR219 transgenic rice line which overexpressed an auxin-binding protein (ABP57) and its wild-type cultivar, MR219, were screened under well-watered (WW) and drought stress (DS) conditions at the early reproductive stage. This study was conducted with the standard planting distance and under a normal environment to assess the yield advantages based on the field conditions. The aim of this study was to understand the response of these rice genotypes towards DS at morpho-physiological, biochemical, and agronomical levels. It was found that the DS had affected all these levels of the genotypes studied; however, the transgenic plant showed a higher number of tillers, flag leaf area, biomass, relative water content, total chlorophyll content, and antioxidative defense mechanism than the MR219 under DS. Compared to its wild-type, the transgenic plant showed an increased leaf photosynthetic rate by 7% under WW and 11% under DS. The transgenic plant also showed higher yields than MR219 under the WW (10%) and DS (59%). The results propose that drought tolerance is significantly improved in the MR219 transgenic rice line. It may develop a new opportunity for the drought-tolerant rice breeding programme via overexpression of ABP57