No abstract

The development of molecular biology techniques nowadays has enabled to engineer drought tolerant sugarcane by genetic engineering to accelerate the breeding program. Dehydrin (DHN) is known to have an important role in plant response and adaptation to abiotic stresses (drought, high salinity, cold, heat, etc.). While plant tissues are subjected to drought stress (dehydration), DHN protein is accumulated to high content throughout all vegetative or generative tissues. The research aimed to isolate and characterize the DHN promoter from sugarcane that can be used as transformation material in generating drought tolerant sugarcane. Specific primers for DHN promoter amplification were designed and DHN promoter region was successfully isolated by PCR cloning method. Two putative promoter sequences were identified namely Pr-1DHNSo and Pr-2DHNSo. In silicoanalyses were carried out and cis-regulatory elements motifs that play a role in adaptation on abiotic stress as well as biotic stress including ABRE, MBS, CGTCA-motif, TGACG-motif, GARE-motif, P-box TCA-element and Box-W1 were identified. The promoter Pr-1DHNSo was then cloned into pBI121 expression vector by Overlap Extention PCR (OE-PCR) for further characterization. Functional test of the promoter construct pBI- Pr-1DHNSo was conducted through Agrobacterium transformation into sugarcane calli. GUS assay and PCR analysis showed that the DHN promoter was transformed and expressed in the sugarcane calli.

Sengon tree (Paraserianthes falcataria (L.) Nielsen) currently becomes a major forest tree species widely planted by smallholders in Indonesia. The wood of this is quick growing and relatively easy to sell. However, level of plant safety sengon between crop plantations and other forestry need to be assessed considering the sengon tree is alternative host of Ganoderma spp. Studies have been conducted to know the presence and diversity of Ganoderma spp. on the sengon tree and some ways inoculation on sengon plant in the nursery. Survey of Ganoderma conducted in several locations of community forests and cacao (Theobroma cacao) plantations in West Java and East Java. Testing of genetic diversity based on RAPD technique.

Drought is one of the limiting factors in crop cultivation, such as in oil palm (Elaeis guineensis Jacq.). The transgenic approaches are expected to increase plant tolerance to drought stress and minimize low productivity when drought occurs. Proline is an osmoprotectant compound in plants which its biosynthesis involved the P5CS gene. The objective of this study was to evaluate the tolerance level of P5CS-transgenic oil palm to drought stress induced by polyethylene glycol 6000 (PEG-6000). In this present study, the transgenic and non-transgenic oil palms were treated by  0, 2, and 4% PEG-6000 under in vitro conditions. The experiment was arranged as a factorial completely randomized design with three replications. The drought level score, total chlorophyll content, carotenoids, and proline content, as well as P5CS gene expression in leaf tissues were observed at 7 and 14 days after stress treatments. The result showed that transgenic plantlets had a lower drought level score than those of non-transgenic lines. A concentration of 4% PEG-6000 treatment reduced the total chlorophyll and carotenoids contents than that of 2% concentration in non-transgenic plantlets at 7 and 14 day after treatments (DAT). In addition, proline content and P5CS gene expression level in transgenic had been significantly increased during stress treatment. Based on these results, it can be concluded that the P5CS transgene increased the drought stress tolerance of oil palm.

Abiotic stress such as drought stress is one of the important factors that affect plant growth. Plants have an adaptation mechanism to overcome the stress condition by accumulating osmoprotectant compounds. Proline is a well known compatible solute and can be accumulated to a high concentration in plant cells under drought or osmotic stress. One of the important enzymes in proline biosynthesis is ∆1 - pyrroline-5-carboxylate synthetase (P5CS) encoded by P5CS gene. This research is aimed to clone partial length of P5CS gene from S. officinarum, variety PSJT 941. The amplification of P5CS gene fragment was done by Reverse Transcription-Polymerase Chain Reaction (RT-PCR), using specific primers. DNA fragment of 984 bp, 975 bp and 1725 bp were cloned into Escherichia coli XL1-Blue using pGEMT Easy plasmid vector. Results from BLAST analysis showed that the P5CS sequences have high homology (99%) with the P5CS gene of S. officinarum in the GenBank database. AbstrakCekaman abiotik seperti kekeringan merupakan salah satu faktor penting yang mempengaruhi pertumbuhan tanaman. Tanaman mempunyai strategi adaptasi dalam mengatasi cekaman tersebut dengan mengakumulasi senyawa osmoprotektan yang terakumulasi dalam konsentrasi tinggi. Prolin merupakan salah satu senyawa osmoprotektan yang dapat melindungi tanaman dari cekaman kekeringan maupun osmotik. Salah satu enzim yang berperan penting dalam biosintesis prolin adalah ∆1 -pyrroline-5- carboxylate synthetase (P5CS) yang disandi oleh gen P5CS. Penelitian ini bertujuan untuk mengklon fragmen gen P5CS dari S. officinarum varietas PSJT 941. Amplifikasi fragmen gen P5CS dilakukan dengan teknik Reverse TranscriptionPolymerase Chain Reaction (RT-PCR) menggunakan primer spesifik gen P5CS. Fragmen DNA hasil RT-PCR berukuran 984 bp, 975 bp, dan 1725 bp diklon ke dalam Escherichia coli XL 1-Blue menggunakan vektor plasmid pGEM-T Easy. Hasil analisis BLAST menunjukkan bahwa sekuen fragmen gen produk RT-PCR yang berasal dari S. officinarum PSJT 941 memiliki homologi yang sangat tinggi (99%) dengan gen P5CS pada S. officinarum yang ada dalam pusat data Genbank.