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Inoculation with arbuscular mycorrhizal (AM) fungi can modify stomatal behavior and increase antioxidant enzyme activities and therefore play a pivotal role in plant growth. We hypothesised that inoculation with AM fungi postpones the non-hydraulic root signal and alters physiological and biochemical traits, which enhances drought tolerance and water-use efficiency (WUEB) for plant biomass. Two pot experiments (including progressive soil drying and partial root-zone drying) were conducted to reveal how mycorrhizal colonization altered root signal and its effects on plant growth, biochemical traits and WUEB in maize seedlings in drying soil. In our experiments, inoculation with Funneliformis mosseae improved water absorption and reduced the sensitivity of roots to drought. In addition, it decreased leaf abscisic acid (ABA) content of inoculated plants. Regardless of water conditions, plant biomass production, antioxidant enzyme activity, net photosynthetic rate, stomatal conductance and WUEB were elevated in AM fungal treatments compared to non-AM fungal treatments. Under water-stressed conditions, inoculation with F. mosseae greatly reduced leaf ABA content, and postponed the decline in photosynthetic rate, stomatal conductance and osmotic adjustment. Malondialdehyde (MDA) level was significantly lower in mycorrhizal plants than in non-inoculation plants. However, inoculation with F. mosseae increased antioxidant enzyme activities including peroxidase (POD) and superoxide dismutase (SOD). In this study, inoculation with F. mosseae reduced ABA accumulation that acts as a non-hydraulic root signal and thereby postponed a decline in stomatal conductance and photosynthetic rate, improved water use efficiency and antioxidant enzymes activities, and accordingly reduced proline and MDA content. Thus, inoculation with AM fungi played a role in effective defense for better drought acclimation in water-stressed maize seedlings.

Inter-simple sequence repeat (ISSR) markers were used to investigate the genetic diversity within and among thirteen natural populations of Camellia japonica (L.). Twenty ISSR primers gave rise to 211 discernible DNA bands of which 190 (90.1%) were polymorphic. On average each primer gave rise to 10.55 bands including 9.50 bands with polymorphic profile. At the species level, high genetic diversity was detected (PPB: 90.1%; HE: 0.3414; H: 0.5013). However, relatively low genetic diversity existed within populations. Shiko-2 exhibits the greatest level of variability (PPB: 76.8%; HE: 0.2966; H: 0.4319), whereas XS presents its own variability at the lowest level (PPB: 67.3%; HE: 0.2344; H: 0.3478). A relatively high level of genetic differentiation among populations was revealed by Nei's gene diversity statistics (21.3%), Shannon's information measure (21.4%) and analysis of molecular variance (AMOVA) (22.5%). There was significant correlation between genetic distance and geographic distance (r = 0.8154, P

The secondary growth is a significant biological activity for plant development, and the secondary xylem (i.e. wood) plays an important role for human life. The secondary growth includes several consecutive processes such as vascular tissue differentiation, secondary cell wall deposition, lignification, PCD and heart wood formation. Considerable evidence indicated that auxin is the major signal involved in several aspects of the ontogeny of the vascular system. At the same time, a suite of putative transcription factors such as MYB, NAC, AP2/EREBP, homeobox and MADS have been implicated in the regulation of the secondary growth. The candidate genes in the signaling and transcriptional regulation which have been identified will assist future investigations to unravel the molecular mechanisms of secondary growth. The important aspect in secondary growth and the identification of regulatory genes were reviewed here.

Ingestion of soft faeces derived from caecal contents, caecotrophy, in herbivorous small mammals is considered an adaptation to the metabolic disadvantage of small body size, especially when feeding on diets of low quality. We investigated daily activity patterns in captive Brandt's voles (Lasiopodomys brandtii), including feeding, locomotion, caecotrophy, and defaecation, by continuous 24 h visual observation; and estimated the contribution of soft faeces ingestion (caecotrophy) to intake of protein and energy. Brandt's voles ingested 68.8 +/- 7.4 fecal pellets per day, averaging 17 +/- 2% of total faeces produced. The amount of faeces ingested did not differ between female and male voles or between night and day time. All animals showed average 3 h ultradian cycles in behaviour during the course of the day and night. The contributions of caecotrophy to the dietary intake of crude protein and metabolizable energy were estimated respectively as 9 and 8% on a high-protein, easily digested commercial rabbit pellet diet. However, the importance of caecotrophy to the field voles is likely to be higher on a natural diet of lower nutrient density. The rhythm of caecotrophy in voles depended mainly on the rhythm of the colonic separation mechanism in the proximal colon and passage in the distal colon, and may be regulated by feeding and other activity rhythms. Ultradian rhythms in caecotrophy helped to minimise potential conflicts in utilizing the gut, especially in balancing the caecal fermentation and salvaging nutrients contained in caecal bacteria.