Arabidopsis pumila is a type of cruciferous ephemeral plant, which in China mainly grows in the desert environments of northern Xinjiang. A. pumila not only has a short growth duration, but also has high photosynthetic efficiency, seed yield, salt tolerance, and drought resistance. It is an ideal species for the study of environmental adaptations in ephemeral plants. We induced callus tissue formation on the roots and hypocotyls of 8-day-old seedlings, and on the leaves and petioles of 4-week-old seedlings, and obtained multiple adventitious shoots on these tissues grown on Murashige and Skoog induction medium supplemented with 0.5 mg/L 6-Benzylaminopurine and 0.1 mg/L α-Naphthalene acetic acid. Young roots, hypocotyls, leaves, and petioles could all induce calluses, but the induction rate was highest on young roots. In addition, the leaves and petioles of 4-week-old seedlings were used as explants, the Δ1-pyrroline-5-carboxylic acid synthase gene 1 of A. pumila controlled by 35S promoter of cauliflower mosaic virus was used as target gene, and hygromycin B was used as screening antibiotic to explore Agrobacterium tumefaciens GV3101 mediated transformation. The results showed that the callus induction rate of petiole explants was the highest when they were treated with Agrobacterium suspension (OD600?=?0.6) for 10 min and thenco-cultured in dark for 2 days. The qRT-PCR results showed that the ApP5CS1.1 gene was overexpressed in the transgenic plants. These protocols provide working research methods for exploring the cellular level adaptative mechanisms of this species to desert environments.
With the expansion of saline land worldwide, it is essential to establish a model halophyte to study the salt‐tolerance mechanism. The salt glands in the epidermis of Limonium bicolor (a recretohalophyte) play a pivotal role in salt tolerance by secreting excess salts from tissues. Despite the importance of salt secretion, nothing is known about the molecular mechanisms of salt gland development. In this study, we applied RNA sequencing to profile early leaf development using five distinct developmental stages, which were quantified by successive collections of the first true leaves of L. bicolor with precise spatial and temporal resolution. Specific gene expression patterns were identified for each developmental stage. In particular, we found that genes controlling salt gland differentiation in L. bicolor may evolve in a trichome formation, which was also confirmed by mutants with increased salt gland densities. Genes involved in the special ultrastructure of salt glands were also elucidated. Twenty‐six genes were proposed to participate in salt gland differentiation. Our dataset sheds light on the molecular processes underpinning salt gland development and thus represents a first step towards the bioengineering of active salt‐secretion capacity in crops. 相似文献