Regulation of leaf senescence in Arabidopsis : isolation and characterisation

The effect of ethylene exposure time on leaf senescence was studied in Arabidopsis accessions Ler-0, Col-0 and Ws-0 and in several old (onset of leaf death) mutants representing different genetic loci. Leaf senescence was observed in 24-day-old plants exposed to ethylene for 3 to 16 days. For ethylene treatments up to 12 days, a longer ethylene exposure time resulted in more senescing leaves in wild type plants. However, a 16-day ethylene treatment reduced senescence symptoms. old mutants differentially responded to varied ethylene exposure times. In old3, old9, old12 and old14 mutants, the same number of leaves turned yellow, regardless of the ethylene exposure time. In old5 and old13, increasing ethylene exposure time from 6 to 16 days resulted in the same number of yellow leaves, but less leaves yellowed in a 3-day treatment. The amounts of senescing leaves in old1-1 and old11 mutants decreased with increases in ethylene exposure time from 6 to 16 days. Thus, multiple OLD genes may act to restrict the induction of senescence by ethylene in an ethylene exposure time-dependent manner. The data substantiate the notion that there is a complex interaction between leaf age and ethylene involving multiple genetic loci.

5-Hydr­oxy-1,7-bis­(1H-indol-3-yl)hepta-1,4,6-trien-3-one hemihydrate

The title compound, C23H18N2O2·0.5H2O, a derivative of the biologically active compound curcumin, crystallizes with two organic mol­ecules and a solvent water mol­ecule in the asymmetric unit. Each of the two independent mol­ecules is close to being planar (the dihedral angles between the indole ring systems are approximately 9 and 12°) and each exists in the keto–enol form. There is an intra­molecular O—H⋯O hydrogen bond between the keto and enol groups. In the crystal, the components interact by way of N—H⋯N, N—H⋯O and O—H⋯O hydrogen bonds

PAV markers in <i>Sorghum bicolour</i>:genome pattern, affected genes and pathways, and genetic linkage map construction

KEY MESSAGE: 5,511 genic small-size PAVs in sorghum were identified and examined, including the pattern and the function enrichment of PAV genes. 325 PAV markers were developed to construct a genetic map. ABSTRACT: Presence/absence variants (PAVs) correlate closely to the phenotypic variation, by impacting plant genome sizes and the adaption to the environment. To shed more light on their genome-wide patterns, functions and the possibility of using them as molecular markers, we generated next generation genome sequencing data for four sorghum inbred lines and used associated bioinformatic pipelines to identify small-size PAVs (40–10 kb). Five thousand five hundreds and eleven genic PAVs (40–10 kb) were identified and found to affect 3,238 genes. These PAVs were mainly distributed on the sub-telomeric regions, but the highest proportions occurred in the vicinity of the centromeric regions. One of the prominent features of the PAVs is the high occurrence of long terminal repeats retrotransposons and DNA transposons. PAVs caused various alterations to gene structure, primarily including the coding sequence variants, intron variants, transcript ablation, and initiator codon changes. The genes affected by PAVs were significantly enriched in those involved in stress responses and protein modification. We used 325 PAVs polymorphic between two sorghum inbred lines Ji2731 and E-Tian, together with 49 SSR markers, and constructed a genetic map, which consisted of 10 linkage groups corresponding to the 10 chromosomes of sorghum and spanned 1,430.3 cM in length covering 97 % of the physical genome. The resources reported here should be useful for genetic study and breeding of sorghum and related species. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00122-015-2458-4) contains supplementary material, which is available to authorized users