Curcuma amada Roxb. (Zingiberaceae), commonly known as mango ginger because its rhizome and foliar parts have a similar aroma to mango. The rhizome has been widely used in food industries and alternative medicines to treat a variety of internal diseases such as cough, bronchitis, indigestion, colic, loss of appetite, hiccups, and constipation. The composition of the volatile constituents in a fresh rhizome of C. amada is not reported in detail. The present study aimed to screen and characterize the composition of volatile organic compound (VOC) in a fresh rhizome of three C. amada (ZO45, ZO89, and ZO114) and one C. longa (ZO138) accessions originated from Myanmar. The analysis was carried out by means of headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS). As a result, 122 VOCs were tentatively identified from the extracted 373 mass spectra. The following compounds were the ten most highly abundant and broadly present ones: ar-turmerone, α-zingiberene, α-santalene, (E)-γ-atlantone, cuparene, β-bisabolene, teresantalol, β-sesquiphellandrene, trans-α-bergamotene, γ-curcumene. The intensity of ar-turmerone, the sesquiterpene which is mainly characterized in C. longa essential oil (up to 15.5–27.5%), was significantly higher in C. amada accession ZO89 (15.707 ± 5.78a) compared to C. longa accession ZO138 (0.300 ± 0.08b). Cis-α-bergamotene was not detected in two C. amada accessions ZO45 and ZO89. The study revealed between-species variation regarding identified VOCs in the fresh rhizome of C. amada and C. longa.

The emissions of volatile organic compounds (VOCs) strongly depend on the plant species and are differently represented in specific taxa. VOCs have a degree of chemical diversity and also can serve as chemotaxonomic markers. Zingiber barbatum Wall. is a wild medicinal ginger plant endemic to Myanmar whose VOC composition has never been screened before. In this study, we screened the rhizome of Z. barbatum to identify the VOC composition by the application of gas chromatography combined with time-of-flight-mass spectrometry (GC-TOF-MS). The resulting VOC profile of Z. barbatum showed that it consists mainly of monoterpenes (21%) and sesquiterpenes (30%). Intraspecific similarities and dissimilarities were found to exist between Z. barbatum genotypes in terms of VOC composition. Four accessions (ZO191, ZO223, ZO217, and the control accession ZO105) collected from the Shan State and Mandalay region of Myanmar were found to share a similar VOC profile, while two accessions (ZO64 and ZO160) collected from the Bago region were found to vary in their VOC profiles compared with the control accession. The two identified compounds, i.e., α-bergamotene and β-(E)-guaiene may serve as discriminative chemical markers for the characterization of Z. barbatum species collected in these three geographical regions of Myanmar. This study represents a first attempt to identify and describe the VOCs in the medicinal species Z. barbatum that have not been reported to date.

Soil salinity is a significant threat to sustainable agricultural production. Plants must adjust their developmental and physiological processes to deal with environmental salt conditions. We previously identified 18 serine-arginine-rich (SR) proteins from cassava (Manihot esculenta Crantz) that play pivotal roles in alternative splicing when encountering the external stress condition. However, functional characterisation of SR proteins is less reported in cassava, which is an important staple crop in the world. In the current study, we found that the expression of cassava spliceosomal component 35-like 30A (MeSCL30A) was significantly induced in response to drought and salt stress. The MeSCL30A overexpressing lines were also obtained in Arabidopsis thaliana L., which flowered earlier when compared with Col-0. Moreover, the MeSCL30A overexpressing lines were hypersensitive to salt and drought stress with lower germination and greening rate in comparison to Col-0. Importantly, soil-grown overexpression lines exhibited salt sensitivity through modulating the reactive oxygen species homeostasis and negatively regulating the gene expression that involved in ionic stress pathway. Therefore, these findings refined the SR protein-coding genes and provided novel insights for enhancing the resistance to environmental stress in plant.

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