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A rapid plantlet regeneration system for Perilla frutescens was established from cotyledon and hypocotyl explants. A maximum of 91.06 % cotyledon and 76.4 % hypocotyl explants could directly produce shoots (3.09 ± 0.18 shoots per explants) on Murashige and Skoog (MS) medium. The optimum hormone combinations were 4.44 µM 6-benzylaminopurine (BA) for cotyledon and 2.22 µM BA + 2.85 µM indole-3-acetic acid (IAA) for hypocotyls. Rooting was induced on half-strength hormone-free MS medium. After transplantation to soil, approximate 80 % of the regenerated plantlets could survive, flower and fruit. Moreover, some morphological abnormalities were found among the regenerated plants.Additional key words: growth regulators, direct organogenesis, morphological abnormalities.⎯⎯⎯⎯ Perilla frutescens L. is an annual herb of Lamiaceae used in traditional medicine of China as well as modern medicine (Makino et al. 2002). Moreover, Perilla frutescens usually have two forms, pigmented red form, whose leaves and stems are deep red-purple, and non-pigmented green form, whose leaves and stems are green. Therefore, it was considered as a model plant to study molecular mechanism of anthocyanin biosynthesis (Saito and Yamazaki 2002). In present study, we focused on establishing a high frequency in vitro regeneration system of Perilla frutescens, aiming to get useful somatic mutants and to pave a way for further genetic manipulation of this plant. To our knowledge, such exploitation on Perilla frutescens has not been done so far.The seeds, kindly provided by Gansu Academy of Agricultural Science, were surface-sterilized in 70 % ethanol for 30 s, then in 0.1 % mercuric chloride for 10 min, and rinsed 4 times (5 min each) in sterile distilled water. The sterilized seeds were placed on Murashige and Skoog (1962; MS) basal medium without any growth regulator in a 200 cm 3 conical flask to germinate at 25 ± 2 °C with 16-h photoperiod (irradiance of 65 µmol m -2 s -1 , cool white fluorescent light). About 3 -5 mm long hypocotyls and 0.2 cm 2 cotyledon segments of 5-d-old seedlings were inoculated onto solidified MS medium supplemented with 3 % sucrose, 0.7 % agar and various combinations of BA, IAA, NAA and 2,4-D. Each combination contained 5 replicates and was repeated three times. The frequencies of shoot regeneration via cotyledon and hypocotyl explants and the number of shoots formed on each explants were counted after 40 d. Meanwhile, the regenerated shoots of 2 -3 cm in length were excised and cultured in half-strength hormone-free MS medium for further elongating and rooting. All the media were adjusted to pH 5.8 using NaOH or HCl and autoclaved at 121 °C for 15 min and all the cultures were maintained at 25 ± 2 °C, 16-h photoperiod (65 µmol m -2 s -1 ) in a chamber.After 5 to 10 d of culture on MS media supplemented with different concentrations of BA and IAA, the cotyledon explants began to swell and produce granular structures on their margins and cut surfaces. Two weeks ⎯⎯⎯⎯

East Asia has experienced long-term warming and drying in the twentieth century.However, a phenomenon known as the "warming hiatus" changed the trend of enhanced soil drying over East Asia. In contrast to the previous long-term drying in the last century, time series of soil moisture showed a shift from a downtrend to uptrend around 2005, and prominent wetting was located in the northeast (semiarid and dry subhumid regions) and southeast of China (extreme humid regions). Our results illustrated that such abrupt change in soil moisture was closely related to the change of warming during hiatus. The warming hiatus played a more important role in decadal soil wetting over these semiarid and dry subhumid regions, compared to relatively limited influence of surface atmosphere temperature over humid regions. The weakened drying during the hiatus decade suggests that the response of wetting/drying to climate in drylands is closely related to decadal surface atmosphere temperature, which will deepen our understanding of the mechanism on the role of surface atmosphere temperature in the process of wetting/drying in drylands over different time scales.