McIntosh Shane, Watson Loraine, Bundock Peter, Crawford Allison, White Jessica, Cordeiro Giovanni, Barbary Daniel, Rooke Lee, Henry Robert
Grain Foods CRC, Centre for Plant Conservation Genetics, Southern Cross University, PO Box 157, Lismore, NSW 2480 Australia.
Plant Biotechnol J. 2007 Jan;5(1):69-83. doi: 10.1111/j.1467-7652.2006.00218.x.
Understanding the development of the cereal caryopsis holds the future for metabolic engineering in the interests of enhancing global food production. We have developed a Serial Analysis of Gene Expression (SAGE) data platform to investigate the developing wheat (Triticum aestivum) caryopsis. LongSAGE libraries have been constructed at five time-points post-anthesis to coincide with key processes in caryopsis development. More than 90,000 LongSAGE tags have been sequenced generating 29,261 unique tag sequences across all five libraries. Tag abundance, generated from cumulative tag counts, provides insight into the redundancy and diversity of each library. Annotation of the 500 most abundant tags spanning development highlights the array of functional groups being expressed. The relative frequency of these more abundant transcripts allows quantitative analysis of patterns of expression during grain development. We have identified activities of cellular proliferation/differentiation, the accumulation of storage proteins and starch biosynthesis. The abundance of calcium-dependent protein kinases indicate their importance in signalling across development. Acquisition of a broad array of defence coincides with storage accumulation and is dominated by inhibitors of amylase activity. Differential expression profiles of abundant tags from each library reveal the coordinated expression of genes responsible for the cellular events constituting caryopsis development. This SAGE platform has also provided a resource of novel sequence and expression information including the identification of potentially useful promoter activities. Further investigations into both the abundant and low expressing transcripts will provide greater insight into wheat caryopsis development and assist in wheat improvement programmes.
了解谷类颖果的发育情况对代谢工程的未来发展至关重要，这有利于提高全球粮食产量。我们开发了一个基因表达序列分析（SAGE）数据平台，用于研究发育中的小麦（普通小麦）颖果。在花后五个时间点构建了长SAGE文库，以与颖果发育的关键过程相匹配。已对超过90,000个长SAGE标签进行了测序，在所有五个文库中产生了29,261个独特的标签序列。由累积标签计数产生的标签丰度，为了解每个文库的冗余度和多样性提供了线索。对跨越发育过程的500个最丰富标签的注释突出了所表达的功能组阵列。这些更丰富转录本的相对频率允许对籽粒发育过程中的表达模式进行定量分析。我们已经确定了细胞增殖/分化活动、贮藏蛋白的积累和淀粉生物合成。钙依赖性蛋白激酶的丰度表明它们在整个发育过程中的信号传导中很重要。大量防御相关基因的获得与贮藏积累同时发生，并且以淀粉酶活性抑制剂为主。每个文库中丰富标签的差异表达谱揭示了负责构成颖果发育的细胞事件的基因的协调表达。这个SAGE平台还提供了新的序列和表达信息资源，包括潜在有用启动子活性的鉴定。对丰富和低表达转录本的进一步研究将为小麦颖果发育提供更深入的了解，并有助于小麦改良计划。
