Genome Sequence of Striga asiatica Provides Insight into the Evolution of Plant Parasitism

Parasitic plants in the genus Striga, commonly known as witchweeds, cause major crop losses in sub-Saharan Africa and pose a threat to agriculture worldwide. An understanding of Striga parasite biology, which could lead to agricultural solutions, has been hampered by the lack of genome information. Here, we report the draft genome sequence of Striga asiatica with 34,577 predicted protein-coding genes, which reflects gene family contractions and expansions that are consistent with a three-phase model of parasitic plant genome evolution. Striga seeds germinate in response to host-derived strigolactones (SLs) and then develop a specialized penetration structure, the haustorium, to invade the host root. A family of SL receptors has undergone a striking expansion, suggesting a molecular basis for the evolution of broad host range among Striga spp. We found that genes involved in lateral root development in non-parasitic model species are coordinately induced during haustorium development in Striga, suggesting a pathway that was partly co-opted during the evolution of the haustorium. In addition, we found evidence for horizontal transfer of host genes as well as retrotransposons, indicating gene flow to S. asiatica from hosts. Our results provide valuable insights into the evolution of parasitism and a key resource for the future development of Striga control strategies.Peer reviewe

A case of mixed connective tissue disease complicated with hypertrophic obstructive cardiomyopathy.

A 54-year-old female was diagnosed as mixed connective tissue disease (MCTD) complicated with secondary Sjogren\u27s syndrome. Although she had no dyspnea on exertion, the chest X-ray showed cardiomegaly with interstitial pneumonia. The echocardiogram demonstrated asymmetric hypertrophy of the interventricular septum. Diagnosis of hypertrophic obstructive cardiomyopathy (HOCM) was confirmed by left ventriculography and myocardial biopsy. She was treated with prednisolone, resulting in improvement of swollen hand, elevated muscle enzymes and interstitial pneumonia. A rare complication of HOCM with MCTD was described

SGA2.02_all_proteins

A multifasta file containing predicted protein sequences from Striga asiatica genome assembly ver2

Sh14Contig_functionalannotation

Functional annotation and GO classification of transcriptome assembly of Striga hermonthica made by blast2GO program

Sh14Contig_protein.fasta

Predicted protein sequences from transcriptome assembly of Striga hermonthica mRNA isolated from seeds, seedlings, 1, 3 and 7-d haustoria. Note this sequences contain gaps

SGA2.02_all_CDS

A multifasta file containing predicted coding sequences from Striga asiatica genome assembly ver. 2

Sh14Contig.fasta

Transcriptome assembly of Striga hermonthica mRNA isolated from seeds, seedlings, 1, 3 and 7-d haustoria. Note this sequences contain gaps