本期《Science》两项研究提出，涉及硼转运的基因帮助植物在毒性生长条件下存活。虽然研究人员还不知道这个微量营养素究竟对植物起什么作用，但是他们知道植物需要适量的硼，太多或太少都对植物的生长不利。硼毒性在赤道附近国家和旱区的农业中最为明显。现在，两项研究对植物如何处理硼提供了一些线索。在一篇报告中，Tim Sutton和澳大利亚的同事描述了克隆一个大麦的硼转运基因、并显示一种特别能耐高硼的大麦有该基因的多个拷贝。在另一篇简报中， Kyoko Miwa和日本的同事揭示，用基因工程改造后过渡表达一个与硼转运有关的基因的拟南芥植物，其生长条件能承受更高的硼。这两篇文章为基因改造作物使其能耐硼、从而适应贫瘠土地种植指出了方法。
原始出处（一）:
Science 30 November 2007:
Vol. 318. no. 5855, pp. 1446 - 1449
DOI: 10.1126/science.1146853
Reports
Boron-Toxicity Tolerance in Barley Arising from Efflux Transporter Amplification
Tim Sutton,* Ute Baumann, Julie Hayes, Nicholas C. Collins, Bu-Jun Shi, Thorsten Schnurbusch, Alison Hay, Gwenda Mayo, Margaret Pallotta, Mark Tester, Peter Langridge
Both limiting and toxic soil concentrations of the essential micronutrient boron represent major limitations to crop production worldwide. We identified Bot1, a BOR1 ortholog, as the gene responsible for the superior boron-toxicity tolerance of the Algerian barley landrace Sahara 3771 (Sahara). Bot1 was located at the tolerance locus by high-resolution mapping. Compared to intolerant genotypes, Sahara contains about four times as many Bot1 gene copies, produces substantially more Bot1 transcript, and encodes a Bot1 protein with a higher capacity to provide tolerance in yeast. Bot1 transcript levels identified in barley tissues are consistent with a role in limiting the net entry of boron into the root and in the disposal of boron from leaves via hydathode guttation.
Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Private Mail Bag 1, Glen Osmond, South Australia 5064, Australia.
* To whom correspondence should be addressed. E-mail: tim.sutton@acpfg.com.au
