科学家利用WIWAM植物表型成像系统发表了题为“Division zone activity determines the potential of drought-stressed maize leaves to resume growth after rehydration”的文章”，研究了玉米胁迫。

分区区活动决定了干旱胁迫玉米叶片在补水后恢复生长的潜力 

摘要

干旱是玉米等作物产量损失最具破坏性的原因之一，预计气候变化导致干旱的严重程度和持续时间会增加，这将对农业生产力构成迫在眉睫的威胁。为了了解干旱响应，通常在干旱开始后的给定时间点进行表型和分子研究，代表稳态适应响应。因为生长是一个动态过程，所以我们以高时间分辨率监测干旱反应，并在第四叶出现后 4 天和 6 天检查补水后的细胞和转录组变化。这些数据表明，分裂区活性是补液后器官完全生长恢复的决定因素。此外，PLASTOCHRON1 的异位表达对细胞分裂的长时间维持延长了再水化后恢复生长的能力。转录组分析还表明，生长调节因子 （GRF） 通过影响细胞分裂持续时间来影响叶片生长，再水化后 GRF1 过表达系的延长恢复潜力证实了这一点。最后，我们使用多重基因组编辑方法来评估转录组研究中最有前途的差异表达基因，从而将基因空间从 40 个基因缩小到 7 个基因，以便进行将来的功能表征。

Division zone activity determines the potential of drought-stressed maize leaves to resume growth after rehydration 

Abstract

Drought is one of the most devastating causes of yield losses in crops like maize and the anticipated increases in severity and duration of drought spells due to climate change pose an imminent threat to agricultural productivity. To understand the drought response, phenotypic and molecular studies are typically performed at a given time point after drought onset, representing a steady-state adaptation response. Because growth is a dynamic process, we monitored the drought response with high temporal resolution and examined cellular and transcriptomic changes after rehydration at 4 and 6 days after leaf four appearance. These data showed that the division zone activity is a determinant for full organ growth recovery upon rehydration. Moreover, a prolonged maintenance of cell division by the ectopic expression of PLASTOCHRON1 extends the ability to resume growth after rehydration. The transcriptome analysis also indicated that GROWTH-REGULATING FACTORS (GRFs) affected leaf growth by impacting cell division duration, which was confirmed by a prolonged recovery potential of the GRF1-overexpression line after rehydration. Finally, we used a multiplex genome editing approach to evaluate the most promising differentially expressed genes from the transcriptome study and as such narrowed down the gene space from forty to seven genes for future functional characterization.

WIWAM line

All traits on the RIL, pGA2ox::PLA1 and GRF1Rlines were measured in a series of experiments in a maize automated Weighing, Imaging and Watering Machine (WIWAM Line). This automated phenotyping platform was designed in collaboration with SMO bvba (Eeklo, Belgium), is located in a controlled-environment growth chamber with the same environmental conditions detailed above and enables automated weighing and

irrigation of plants according to a preset scheme, specific for each plant or group of plants. In this system, up to 155 maize plants can be grown until V7 and can be watered with 1 ml precision to a fixed volume or to varying target weights by watering the plants in a circular motion around the stem at approximately 5 cm distance from the plant. Briefly, a robotic arm takes a pot from the platform and brings it to the weighing and watering station. While watering, the pot is rotated until the target weight is reached. Subsequently, the robotic arm places the pot back on the platform and proceeds to the next pot. The robot pushes the lines of the table aside to create the required space in between for the robotic arm to locate a pot and lift it out of the table. The WIWAM Line can be adjusted for different growth rooms, crops, pot sizes and nutrient solutions, and the weighing and watering station can be equipped with an imaging station where pictures of each plant can be taken daily to monitor plant growth.