Rice grain with excessive cadmium (Cd) is a major source of dietary Cd intake and a serious threat to health for people who consume rice as a staple food. The development of elite rice cultivars with consistently low Cd content is challenging for conventional breeding approaches, and new strategies urgently need to be developed. Here, we report the development of new indica rice lines with low Cd accumulation and no transgenes by knocking out the metal transporter gene OsNramp5 using CRISPR/Cas9 system. Hydroponic culture showed that Cd concentrations in shoots and roots of osnramp5 mutants were dramatically decreased, resulting in rescue of impaired growth in high Cd condition. Cd-contaminated paddy field trials demonstrated that Cd concentration in osnramp5 grains was consistently less than 0.05 mg/kg, in contrast to high Cd concentrations from 0.33 mg/kg to 2.90 mg/kg in grains of Huazhan (the wild-type indica rice). In particular, the plant yield was not significantly affected in osnramp5 mutants. Furthermore, we developed promising hybrid rice lines with extremely low Cd content in grains. Our work supplies a practical approach to developing Cd pollution-safe indica rice cultivars that minimizes Cd contamination risk in grains.

The hydrochloric acid/methanol-ultrasonic extraction has the best effect for three medicinal components of fresh bark, providing an extraction yield of 103.12 mg/g berberine, 24.41 mg/g phellodendrine, 1.25 mg/g palmatine.

Protein phosphatases, together with protein kinases, regulate protein phosphorylation and dephosphorylation, and play critical roles in plant growth and biotic stress responses. However, little is known about the biological functions of plant protein tyrosine dual-specificity phosphatase (PFA-DSP) in biotic stresses. Here, we found that OsPFA-DSP2 was mainly expressed in calli, seedlings, roots, and young panicles, and localized in cytoplasm and nucleus. Ectopic overexpression of OsPFA-DSP2 in rice increased sensitivity to Magnaporthe grisea (M. grisea Z1 strain), inhibited the accumulation of hydrogen peroxide (H2O2) and suppressed the expression of pathogenesis-related (PR) genes after fungal infection. Interestingly, transgenic Arabidopsis plants overexpressing AtPFA-DSP4, which is homologous to OsPFA-DSP2, also exhibited sensitivity to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), reduced accumulation of H2O2 and decreased photosynthesic capacity after infection compared with Col-0. These results indicate that OsPFA-DSP2 and AtPFA-DSP4 act as negative regulators of the pathogen response in transgenic plants.

Using seedlings as material, and treated with different concentrations of exogenous 6-Benzylaminopurine (6-BA) and α-naphthyacetic acid (NAA), then observed the growth status. Furthermore, we detected the contents of chlorophyll and soluble sugar, the activities of antioxidases by spectrophotometry, and determined the contents of secondary metabolite by high performance liquid chromatograph. The results showed that different concentrations of exogenous 6-BA increases the fresh weights and plant heights of seedlings, and enhances the contents of chlorophyll and soluble sugar. NAA promoted growth, but deduced the contents of soluble sugar. Compared with control, culturing for 40 d, proper concentrations 6-BA enhanced the activity levels of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), proper concentrations NAA increased the activity levels of SOD and CAT, but decreased the levels of POD compared with CK. Suitable concentrations 6-BA enhanced contents of berberine, phellodendrine and palmatine in stems, proper concentrations NAA increased contents of berberine and phellodendrine, but deduced contents of palmatine compared with CK. Based on these results, we concluded that the exogenous 6-BA and NAA had key regulation on the growth and contents of medicinal ingredient of seedlings.

By the systematical optimization on explants sterilizing, induction and multiplication of adventitious shoots, rooting and seedling transplanting, the high-efficient regeneration system and domestication transplanting technology for red pitaya (Hylocereus polyrhizus) were established using dormant buds in spine base as primary materials. Results showed that the optimal surface sterilization procedure of red pitaya explants (nodal segments with one spine base) was 0.2% mercuric chloride (HgCl 2 ) treatment for 7 min. The appropriate medium formulation for adventitious shoot induction and proliferation of sterilized red pitaya explants was Murashige and Skoog's medium (MS) supplemented with 5.5 mg/L 6-benzyladenine (6-BA) and 0.1mg/L α-naphthaleneacetic acid (NAA), and maximum average number (6.4) of adventitious shoots per explant and maximum average plantlet height (2.8 cm) were achieved within 30 days. An optimal formulation of half-strength MS medium (1/2 MS) added with 0.5 mg/L NAA and 0.3 mg/L indole-3-butyricacid (IBA) produced an average of 7.21 roots per explant with highest (92%) rooting response when inoculating 4 adventitious shoots per bottle. The tissue-cultured seedlings of red pitaya display a survival rate of up to 100% by optimized procedure of domestication and transplantation.

The fatty acid compositions of Jatropha oil and Vernicia oil are strikingly different, which leads to a great difference in combustion performance, low temperature performance and oxidation stability. A comparative transcriptomic study was made in Vernicia and Jatropha, with a focus on the gene regulation of differential oil accumulation process. Transcriptome sequencing was conducted with seeds at the initial-and fast-stage of oil accumulation from both. More than 24 billion bases of cDNA sequence were obtained, with 49,583 and 45,414 high-quality unigenes identified for Vernicia and Jatropha seeds, respectively. Multiple comparative transcriptome approaches revealed a number of species-specific fatty acid desaturases (FAD2, FADX, FAH12 etc.) contributing to their differentiated fatty acid compositions in seeds of Vernicia and Jatropha. Meanwhile, the results suggested that DGAT majorly regulates TAG synthesis than PDAT in Vernicia seed, and PDAT may have more important role regulating TAG synthesis in Jatropha seed than in Vernicia seed. It was also implied that specific oleosins involving in oil bodies may have member bias and may affect lipid contents in seeds of Vernicia and Jatropha, as some of which were 30-50 fold up-regulated (with their RPKM values over 10,000 at fast-stage). Some important factors were identified and can differentially regulate lipid pathways in seeds of Vernicia and Jatropha.

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