Isolation and Physiological Characterization of Synechococcus cedrorum 1191 Strain Tolerant to Heavy Metals and Pesticides

The toxicity of heavy metals (Hg2 + , Zn2 + ) and pesticides has been investigated by comparing the physiological properties in wild and tolerant strains of Synechococcus cedrorum 1191. The differential pattern of growth, absorption spectra of pigments and nutrient uptake was observed in tolerant strain.

Transcriptomic and physiological analyses identifying Lanzhou lily(Lilium davidii var.unicolor)drought adaptation strategies

Drought stress is the main limiting plant growth factor in arid and semiarid regions.The Lanzhou lily(Lilium davidii var.unicolor)is the only sweet-tasting lily grown in these regions of China that offers highly edible,medicinal,health,and ornamental value.The Tresor lily is an ornamental flower known for its strong resistance.Plants were grown under three different drought intensity treatments,namely,being watered at intervals of 5,15,and 25 d(either throughout the study or during specific growth stages).We measured the biomass,leaf area,photosynthetic response,chlorophyll content(SPAD value),and osmoregulation of both the Lanzhou lily and the Tresor lily(Lilium‘Tresor’).Additionally,we employed RNA sequencing(RNA-Seq)and qRT-PCR to investigate transcriptomic changes of the Lanzhou lily in response to drought stress.Results showed that under drought stress,the decreasing rate in the Lanzhou lily bulb weight was lower than the corresponding Tresor lily bulb rate;the net photosynthetic rate,transpiration rate,and stomatal conductance of the Lanzhou lily were all higher compared to the Tresor lily;osmoregulation constituents,such as glucose,fructose,sucrose,trehalose,and soluble sugar,in the Lanzhou lily were comparatively higher;PYL,NCED,and ERS genes were significantly expressed in the Lanzhou lily.Under moderate drought,the biosynthesis of flavonoids,circadian rhythms,and the tryptophan metabolism pathway of the Lanzhou lily were all significant.Under severe drought stress,fatty acid elongation,photosynthetic antenna protein,plant hormone signal transduction,flavone and flavonol biosynthesis,and the carotenoid biosynthesis pathway were all significant.The Lanzhou lily adapted to drought stress by coordinating its organs and the unique role of its bulb,regulating photosynthesis,increasing osmolyte content,activating circadian rhythms,signal transduction,fatty acid elongation metabolism,and phenylalanine and flavonoid metabolic pathways,which may collectively be the main adaptation strategy and mechanisms used by the Lanzhou lily under drought stress.

Effects of Zinc on Physiologic Characterization and Cadmium Accumulation and Chemical Forms in Different Varieties of Pepper

The effects of zinc （Zn） at different spray concentra- tions （0, 500, and 1 000 μmol · L-1 ） on the plant growth, the ac- tivities of antioxidant enzymes chemical forms of cadmium （Cd）, and the accumulation of Cd were studied and compared between two varieties, Shijichaotianjiao （SJCTJ） and Yanjiao425 （YJ425） of pepper （Capsicum annuum L.） in Cd-contaminated soil （Cd 10 mg @ kg-1 ）. The activities of catalase （CAT） and peroxidase （POD） were generally enhanced by Zn. However, superoxide dismutase （SOD） decreased. Addition of Zn decreased the ethanol-extract- able Cd, NaCl-extractable Cd, and acetic acid-extractable Cd in the fruit by 34.6%- 55.3%, 2.0%-17.7% and 0.4%-32.9%, and reduced the accumulation of Cd in fruit and plant total Cd by 12.8%- 68.6% and 9.0%-29.3% in both varieties, respectively.

Effect of Exogenous Lanthanum on Accumulation of Cadmium and Its Chemical Form in Tomatoes

In the condition that soil is polluted by Cd（20 mg·L-1）,two varieties of tomato（Lycopersicon esculintum Mill.）（plant high Cd-enriched variety（Yufen109）and plant low Cd-enriched variety（4641））treated with LaCl3 of different concentration（0,10 and 20mg·L-1）were determined for their effect on plant dry weight,anti-oxidase activity（CAT,SOD and POD）,tomato fruit Cd chemical form and Cd accumulation.The results show that 10 mg？L-1LaCl3 can increase dry weight of plant at various positions and can reduce the concentration of Cd of different forms.Spraying with LaCl3（10,20 mg·L-1）can reduce Cd concentration in leaves,stems,roots and fruits of tomato plants with lowering rates of 13.7%-31.9%,9.5%-30.6%,10.8%-44.5%and 19.4%-37.0%,respectively.Suitable amount of lanthanum（10 mg·L-1 LaCl3）can increase yield of tomatoes,reduce Cd accumulation in the fruit.In the two tomato varieties,Lanthanum and Cadmium react interactively,expressing to be coexisting of both synergism and antagonistic.