Physiological Characteristic Changes and Full-Length Transcriptome of Artemisia sphaerocephala in Response to Drought Stress

Background: Artemisia sphaerocephala is an important sand-fixing plant in arid sandy areas. To elucidate the physiological and molecular changes of A. sphaerocephalala induced by drought stress, this study used a combination of sec-ond-generation sequencing and third-generation sequencing technologies to sequence the full-length transcriptome of A. sphaerocephalala to identify significant genes and major pathways associated with drought resistance.Results: Changes in physiological characteristics indicated that relative permeability of plasma (RPP), superoxide dis-mutase (SOD) activity, peroxidase (POD) activity, catalase (CAT) activity, malondialdehyde (MDA), proline(Pro), solu-ble sugar(SS), soluble protein(SP) contents increased under drought stress, and all of them decreased sharply after re-watering. The relative water content under drought stress showed a decreasing trend, but it increased after re-watering and the chlorophyll content showed a continuous decrease under drought stress and re-watering. Addition-ally, transcriptome sequencing revealed that important metabolic pathways, such as Plant hormone signal transduction, Starch and sucrose metabolism, Glyoxylate and dicarboxylate metabolism, and Nitrogen metabolism were enriched in A. sphaerocephala under severe drought stress. Moreover, the RNA-Seq results of 10 genes were confirmed by real-time PCR, and the results showed that all of them were involved in the process of drought stress adaptation of A. sphaero-cephala.Conclusions: This is the first reported large-scale sequencing of the full-length transcriptome of A. sphaerocephala under drought stress, and these results will provide a better understanding of A. sphaerocephala responses to drought stress and lay the groundwork for analyzing the expression profile of genes related to drought tolerance in plants.