Strategies of desiccation tolerance vary across life phases in the moss Syntrichia caninervis
Strategies of desiccation tolerance vary across life phases in the moss Syntrichia caninervis
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DOI：
10.1002/ajb2.1571
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发表时间：
2020-11-29
影响因子：
3
通讯作者：
Stark, Lloyd R.
中科院分区：
文献类型：
--
作者：
Coe, Kirsten K.;Greenwood, Joshua L.;Stark, Lloyd R.
摘要：耐旱性是陆生植物普遍存在的现象，可能存在不同的耐旱生态对策。使用Syntrichia caninervis，旱地苔藓和DT研究中使用的模型系统，我们假设DT是最低的少年（原丝）组织，最高的无性生殖繁殖体（芽），和中间的成年人（芽）。我们测试了长期存在的假设DT在这个species.METHODS固有的组成策略：植物迅速干燥到平衡相对湿度（RHeq）范围从0到93%的水平。使用叶绿素荧光、再生率和可见组织损伤评估水化后恢复。对于每个生命阶段，我们估计的最低干燥速率（RoD（分钟））在RHeq = 42%，没有引起损害24 h postrehydration.RESULTS：DT策略随生命阶段而变化，具有最低的RoD（分钟）（10-25分钟），其次是芽（3-10小时）和原丝体（14-20小时）。仅在所用的最高RHeq（93%）下快速干燥后，成年枝条在水合后24小时未表现出可检测的损伤，但当干燥至较低RHs时，响应下降至约20%。
PREMISE: Desiccation tolerance (DT) is a widespread phenomenon among land plants, and variable ecological strategies for DT are likely to exist. Using Syntrichia caninervis, a dryland moss and model system used in DT studies, we hypothesized that DT is lowest in juvenile (protonemal) tissues, highest in asexual reproductive propagules (gemmae), and intermediate in adults (shoots). We tested the long-standing hypothesis of an inherent constitutive strategy of DT in this species.METHODS: Plants were rapidly dried to levels of equilibrating relative humidity (RHeq) ranging from 0 to 93%. Postrehydration recovery was assessed using chlorophyll fluorescence, regeneration rates, and visual tissue damage. For each life phase, we estimated the minimum rate of drying (RoD(min)) at RHeq = 42% that did not elicit damage 24 h postrehydration.RESULTS: DT strategy varied with life phase, with adult shoots having the lowest RoD(min) (10-25 min), followed by gemmae (3-10 h) and protonema (14-20 h). Adult shoots exhibited no detectable damage 24 h postrehydration following a rapid-dry only at the highest RHeq used (93%), but when dried to lower RHs the response declined to