Gossypol: phytoalexin of cotton

Sesquiterpenoids are a class of 15-carbon secondary metabolites that play diverse roles in plant adaptation to environment.Cotton plants accumulate a large amount of sesquiterpene aldehydes(including gossypol)as phytoalexins against pathogens and herbivores.They are stored in pigment glands of aerial organs and in epidermal layers of roots.Several enzymes of gossypol biosynthesis pathway have been characterized,including 3-hydroxy-3-methylglutaryl coenzyme A reductase(HMGR)and farnesyl diphosphate synthase(FPS)that catalyze the formation of the precursor farnesyl diphosphate(FPP),(+)-δ-cadinene synthase(CDN)which is the first enzyme committed to gossypol biosynthesis,and the downstream enzymes of CYP706B1 and methyltransferase.Expressions of these genes are tightly regulated during cotton plants development and induced by jasmonate and fungi elicitors.The transcription factor Ga WRKY1 has been shown to be involved in gossypol pathway regulation.Recent development of new genomic platforms and methods and releases of diploid and tetraploid cotton genome sequences will greatly facilitate the elucidation of gossypol biosynthetic pathway and its regulation.

Transcriptome analysis of three cotton pests reveals features of gene expressions in the mesophyll feeder Apolygus lucorum

The green mirid bug Apolygus lucorum is an agricultural pest that is known to cause damage to more than 150 plant species.Here,we report the transcriptomes of A.lucorum at three different developmental stages(the second and fifth instar nymphs and adults).A total of 98,236 unigenes with an average length of l,335 nt was obtained,of which 50,640 were annotated,including those encoding digestive enzymes and cytochrome P450 s.Comparisons with cotton bollworm and cotton aphid transcriptomes revealed distinct features of A.lucorum as a mesophyll feeder.The gene expression dynamics varied during development from young nymphs to adults.The high-quality transcriptome data and the gene expression dynamics reported here provide valuable data for a more comprehensive understanding of the physiology and development of mirid bugs,and for mining targets for their control.

Engineering purple rice for human health

Human history of domestication of wild plants as food source has witnessed continuous improvement in nutritional qualities of plant products.However,some nutritional traits were lost during agricultural breeding(Tieman et al.,2017),and some are absent in certain wild ancestors and could

RNAi technology for plant protection and its applicatior in wheat

The RNAi technology takes advantage of the intrinsic RNA interference(RNAi)mechanism that exists in nearly all eukaryotes in which target mRNAs are degraded or functionally suppressed.Significant progress has been made in recent years where RNAi technology is applied to several crops and economic plants for protection against diseases like fungi,pests,and nematode.RNAi technology is also applied in controlling pathogen damages in wheat,one of the most important crops in the world.In this review,we first give a brief introduction of the RNAi technology and the underneath mechanism.We then review the recent progress of its utilization in crops,particular wheat.Finally,we discuss the existing challenges and prospect future development of this technology in crop protection.