<p style="text-indent:0px; line-height:12px;"><span style="font-weight:bold;line-height:130%"> Davis, CA</span><hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">By ANUK Staff<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">3.29.13</p><hr class="legacyRuler"><hr class="invisible minimal-padding"><p>Researchers at the University of California, Davis have identified a lettuce gene and enzyme that prevents germination during hot weather – which could lead to lettuces that sprout year-round, even at high temperatures.<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">This study finds particular relevance in California and Arizona where lettuce industries bring in nearly $2 billion and produce more than 90% of the country’s lettuce. <img src="https://cdn.andnowuknow.com/legacyWriterImages/lettuce-research-march-29-2013-cropped.jpg" alt="IMAGES MARCH 29 2013" />“Discovery of the genes will enable plant breeders to develop lettuce varieties that can better germinate and grow to maturity under high temperatures,” said the study’s lead author Kent Bradford, a professor of plant sciences and director of the UC Davis Seed Biotechnology Center.<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">“And because this mechanism that inhibits hot-weather germination in lettuce seeds appears to be quite common in many plant species, we suspect that other crops also could be modified to improve their germination,” he said. “This could be increasingly important as global temperatures are predicted to rise.”<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">Most lettuce varieties flower in spring or early summer and then drop their seeds .The built-in dormancy mechanism seems to prevent lettuce seeds from germinating under conditions that would be too hot and dry to sustain growth, which represents an obstacle to commercial lettuce production.<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">In order to jump-start seed germination for a winter crop in hot climates, lettuce growers have turned to cooling the soil with sprinkler irrigation or priming the seeds to germinate by pre-soaking them at cool temperatures and re-drying them before planting — methods that are expensive and not always successful.<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">Researchers identified a region of chromosome six in a wild ancestor of commercial lettuce varieties that enables seeds to germinate in warm temperatures. When that chromosome region was crossed into cultivated lettuce varieties, those varieties gained the ability to germinate in warm temperatures.<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">The study zeroed in on a specific gene that governs production of a plant hormone called abscisic acid — known to inhibit seed germination. The newly identified gene “turns on” in most lettuce seeds when the seed is exposed to moisture at warm temperatures, increasing production of abscisic acid. In the wild ancestor that the researchers were studying, however, this gene does not turn on at high temperatures. As a result, abscisic acid is not produced and the seeds can still germinate.<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding">The researchers then demonstrated that they could either “silence” or mutate the germination-inhibiting gene in cultivated lettuce varieties, thus enabling those varieties to germinate and grow even in high temperatures.<hr class="legacyRuler"><hr class="legacyRuler"><hr class="invisible minimal-padding"><a class="btn btn-sm btn-primary col-lg-12" style="white-space: normal;" href=" http://www.news.ucdavis.edu/search/news_detail.lasso?id=10546" target="_new">Lettuce Study </a></p><hr class="legacyRuler"><hr class="invisible minimal-padding">
