Waterlogging seriously constrains growth and yields in oil palm. To date, the responsive molecular changes caused by waterlogging in oil palm remain elusive. To elucidate the molecular genetic mechanisms of waterlogging stress, two varieties of oil palm Deli x Lamé and Deli x Ghana were used. The transcriptome profiles of the roots under waterlogging stress and normal conditions were compared via Ion Torrent Sequencing. Four libraries (GNR, GSR, SNR, and SSR) of oil palm roots after 45 days of normal watering and waterlogging stress were constructed. Approximately 6.2 million sequenced reads per library were obtained, with 5.5 million mapped reads (88.64%) similar to the oil palm genome in the GenBank database. A comparison of GNR/GSR showed a high of 3,289 DEGs with most genes up-regulated (1,863 DEGs). The GO analysis revealed the distribution of the DEGs among various pathways, suggesting a wide spectrum of physiological processes impacted by waterlogging stress. Moreover, qRT-PCR showed strong expression of all selected RNA-seq genes in waterlogged Deli x Ghana (GSR), especially GST, SAPK10 and NAC29 that are reported for the time to respond to waterlogging stress. Thus, this study not only reveals the comprehensive mechanisms of waterlogging responsive transcription in oil palm, but also establishes Deli x Ghana as a highly-adaptable variety to waterlogging conditions.

ACC -1-aminocyclopropane-1-carboxylic acid; ACO -1-aminocyclopropane-1-carboxylic acid oxidase; ACO1 -1aminocyclopropane-1-carboxylate oxidase 1; ACS -1-aminocyclopropane-1-carboxylic acid synthase; ACS3 -1-aminocyclopropane -1-carboxylate synthase 3; CAMTA4 -calmodulin-binding transcription activator 4; CEL12 -endoglucanase 12; CML11 -calmodulin 11; CPI1 -cysteine proteinase inhibitor 1; ERF1 -ethylene-responsive transcription factor 1; ERF1B -ethylene-responsive transcription factor 1B; ERF91 -ethylene-responsive transcription factor 91; ERF113 -ethylene-responsive transcription factor 113; bHLH79transcription factor bHLH 79; bHLH94 -transcription factor bHLH 94; HSFA2C -heat shock protein factor A-2c; MYB1R1 -transcription factor MYB1R1; NAC29 -NAC transcription factor 29; PCD -programmed cell death; TCTP -translationally controlled tumor protein; XTH22 -xyloglucan endotransglucosylase/hydrolase protein 22; XTH23 -xyloglucan endotransglucosylase/hydro-lase protein 23; WRKY4 -transcription factor WRKY 4; TF -transcription factor.

Drought is a major constraint in oil palm (Elaeis guineensis Jacq.) production. As oil palm breeding takes a long time, molecular markers of genes related to drought tolerance characteristics were developed for effective selection. Two methods of gene identification associated with drought, differential display reverse transcription polymerase chain reaction (DDRT-PCR) and pyrosequencing platform, were conducted before developing the EST-SSR marker. By DDRT-PCR, fourteen out of twenty-four primer combinations yielded the polymorphism in leaf as 77.66% and root as 96.09%, respectively. BLASTN and BLASTX revealed nucleotides from 8 out of 236 different banding similarities to genes associated with drought stress. Five out of eight genes gave a similarity with our pyrosequencing sequencing database. Furthermore, pyrosequencing analysis of two oil palm libraries, drought-tolerant, and drought sensitive, found 117 proteins associated with drought tolerance. Thirteen out of sixty EST-SSR primers could be distinguished in 119 oil palm parents in our breeding program. All of our found genes revealed an ability to develop as a molecular marker for drought tolerance. However, the function of the validated genes on drought response in oil palm must be evaluated.

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Seven new carnivorous plant cultivars are named and described: Darlingtonia californica 'Iago', Dionaea muscipula 'EGAC Smurf', Dionaea 'PFT Carcharoth', Nepenthes ampullaria 'Black Rainbow', Pinguicula zecheri 'Faulisi', Sarracenia 'Templar Cross', Sarracenia flava var. rubricorpora 'Valkyrie'.