A novel lipoxygenase gene from developing rice seeds confers dual position specificity and responds to wounding and insect attack

OsLOX1 is a novel full-length cDNA isolated from developing rice seeds. We have examined its biochemical properties and expression patterns. The protein has dual positional specificity, as it releases both C-9 and C-13 oxidized products in a 4:3 ratio. OsLOX1 transcripts were detected at low abundance in immature seeds and newly germinated seedlings, but accumulate rapidly and transiently in response to wounding or brown planthopper (BPH) attack, reaching a peak 3 h after wounding and 6 h after insect feeding. We produced transgenic rice lines carrying either sense or antisense constructs under the control of a cauliflower mosaic virus 35S promoter, and these rice lines showed altered OsLOX1 activity. In all of the antisense lines and more than half of the sense lines the expression levels of OsLOX1, the levels of enzyme activity, and the levels of the endogenous OsLOX1 products (jasmonic acid, (Z)-3-hexenal and colneleic acid) at 6, 48, and 48 h after BPH feeding respectively, were below the levels found in non-transgenic control plants; yet, the levels in the remaining sense transformants were enhanced relative to controls. Transformants with a lower level of OsLOX1 expression were less able to tolerate BPH attack, while those with enhanced OsLOX1 expression were more resistant. Our data suggest that the OsLOX1 product is involved in tolerance of the rice plant to wounding and BPH attack.

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Transgenic animal production and animal biotechnology

Considerable progress has been made in methods for production of transgenic livestock; beginning with pronuclear microinjection over 20 years ago. New methods, including the use of viral vectors, sperm-mediated gene transfer and somatic cell cloning, have overcome many of the limitations of pronuclear microinjection. It is now possible to not only readily make simple insertional genetic modifications, but also to accomplish, more complex, homozygous gene targeting and artificial chromosome transfer in livestock.

Source: Theriogenology, Vol 67, 2007, Pages 127-133

Genes to feed the world: The weakest link?

The new science of genomics has an important contribution to make to the development of agriculture in the ‘Third World’ and thus to improving the livelihoods of many of the poorest people on earth. The persistence of poverty demonstrates, however, that this contribution is not yet being made. We therefore examine the web of connections between the two and enquire whether they could be strengthened in some way, perhaps by the addition of some vital ‘missing link’, so that the contribution from genomics can be maximised. Since the use of molecular markers to help develop improved crop varieties (marker-assisted selection) constitutes one of the main ways in which genomic knowledge could be used to improve rural livelihoods, we review this technology and discuss the ways in which it could contribute to plant breeding. We argue that marker-assisted selection (MAS) is likely to be most effective when it is both (i) linked to the farmers who are expected to cultivate the new crop varieties that will eventually be developed; and (ii) integrated with plant breeding and with a range of complementary disciplines. Such integration necessarily involves the formation of effective trans-disciplinary teams, an undertaking that is often problematic, and so the final part of this article considers the processes that this involves and suggests ways in which they may be managed effectively.

Adapted from Food Policy, Vol 32, 2007, Pages 459-479