Identification of birch lncRNAs and mRNAs responding to salt stress and characterization of functions of lncRNA

Long noncoding RNAs(lncRNAs)are important in abiotic stress tolerance.Here,we identified salt-responsive genes and lncRNAs in the roots and leaves of Betula platyphylla Suk.(birch),and characterized their lncRNAs functions.In total,2660 mRNAs and 539 lncRNAs responding to salt treatment were identified using RNA-seq.The salt-responsive genes were substantially enriched in‘cell wall biogenesis’and‘wood development’in the roots and were enriched in‘photosynthesis’and‘response to stimulus’in the leaves.Meanwhile,the potential target genes of the salt-responsive lncRNAs in roots and leaves were both enriched in‘nitrogen compound metabolic process’and‘response to stimulus’.We further built a method for quickly identifying abiotic stress tolerance of lncRNAs,which employed transient transformation for overexpression and knock-down of the lncRNA,enabling gain-and loss-of-function analysis.Using this method,11 randomly selected salt-responsive lncRNAs were characterized.Among them,six lncRNAs confer salt tolerance,two lncRNAs confer salt sensitivity,and the other three lncRNAs are not involved in salt tolerance.In addition,a lncRNA,LncY1,was further characterized,which improves salt tolerance by regulating two transcription factors,BpMYB96 and BpCDF3.Taken together,our results suggested that lncRNAs play important roles in the salt response of birch plants.

Fraction Distribution and Risk Assessment of Heavy Metals in Soils around the Mining Area in Zhijin

The pollution characteristics of Cd,Cr,Cu,Zn,Ni and Hg in agricultural soil around coal mining area were studied. After longterm mining activity,the soil around mining area was polluted by 6 elements to different degrees. Especially for Cd,its concentration was 3. 2times that of the National Soil Environmental Quality Standard Ⅱ. The values suggest that the contamination degree from strong to weak in soil is in the order of Hg > Cu > Cr > Zn > Ni > Cd. BCR sequential extraction results show that the order of average percentage about weak acid soluble fraction( F1) is that Cd > Ni > Zn > Cu > Hg > Cr,the order of 6 heavy metals available fraction( F1 + F2 + F3) is that Cu( 56. 89) > Cd( 50. 95) > Ni( 41. 52) > Zn( 35. 06) > Hg( 23. 04) > Cr( 4. 88). The RAC results indicate that soils were in a moderate potential ecological risk by pollution of Cd,and at the same time,Cu,Zn,Ni,Hg should be noted.