科学家刚刚发表了题为“Drought and recovery in barley: key gene networks and retrotransposon response ”的文章。今年利用Plantarray植物功能生理表型研究系统已经发表了数篇论文。

Plantarray是一款基于称重的高通量、多传感器生理表型平台以及植物逆境生物学研究通用平台。该系统可持续、实时测量位于不同环境条件下、阵列中每个植株的土壤-植物-空气（SPAC）中的即时水流动。直接测量根系和茎叶系统水平衡和生物量增加，计算植物生理参数以及植物对动态环境的反馈。系统以有效、易用、无损的方式针对植物对不同处理的反应、预测植物生长和生产力进行定量比较，广泛应用于生物胁迫和非生物胁迫以及植物栽培加速育种研究等，胁迫研究涵盖干旱胁迫、盐胁迫、重金属胁迫、热、冷胁迫、光胁迫以及灌溉/养分、CO2指示、植物健康等领域的研究。 

摘要

在干旱期间，植物在临界土壤含水量（SWC）下关闭气孔，同时产生不同的生理、发育和生化反应。使用精密表型分析仪，我们对四个大麦品种（Arvo、Golden Promise、Hankkija 673和Morex）进行了开花前干旱处理，并跟踪了它们的生理反应。对于Golden Promises品种，我们在干旱前、干旱期间和恢复期间对叶片转录物进行了RNA-seq，还检测了反转录转座子BARE1的表达。对转录数据进行了网络分析。

不同品种的关键SWC不同，Hankkija673的反应最强烈，GoldenPromise的反应最弱。干旱期间，与干旱和盐度反应相关的途径被强烈上调；与生长发育相关的途径被强烈下调。在恢复过程中，生长和发育途径被上调；共有117个参与泛素介导的自噬的网络化基因被下调。对SWC的不同反应表明对不同降雨模式的适应。

我们在大麦中鉴定了几个早期与干旱反应无关的强差异表达基因。BARE1转录在干旱时被强烈转录上调，而在恢复过程中被下调，这在所研究的品种之间是不相等的。网络自噬基因的下调表明自噬在干旱反应中发挥作用；应进一步研究其对复原力的重要性。 

关键词：大麦（Hordeum vulgare L.）；干旱恢复力恢复基因表达分析；BARE逆转录转座子；自噬

Drought and recovery in barley: key gene networks and retrotransposon response

SUMMARY

During drought, plants close their stomata at a critical soil water content (SWC),together with diverse physiological, developmental, and biochemical responses. Using precision-phenotyping lysimeters, we imposed pre-flowering drought on four barley varieties (Arvo, Golden Promise, Hankkija 673 and Morex and followed their physiological responses. For Golden Promise, we carried out RNA-seq on leaf transcripts before and during drought, and during recovery, also examining retrotransposon BARE1 expression. Transcriptional data were subjected to network analysis.

The varieties differed by their critical SWC, Hankkija 673 responding at the highest and Golden Promise at the lowest. Pathways connected to drought and salinity  response were strongly upregulated during drought; pathways connected to growth and development were strongly downregulated. During recovery, growth and development pathways were upregulated; altogether 117 networked genes involved in ubiquitin-mediated autophagy were downregulated. The differential response to SWC suggests adaptation to distinct rainfall patterns. 

We identified several strongly differentially expressed genes not earlier associated with drought response in barley. BARE1 transcription is strongly transcriptionally  upregulated by drought and downregulated during recovery unequally between the investigated cultivars. The downregulation of networked autophagy genes suggests a role for autophagy in drought response; its importance to resilience should be  further investigated. 

Key words: Barley (Hordeum vulgare L.); drought; resilience; recovery; gene expression analysis; BARE retrotransposon; autophagy