Contrasting strategies to cope with chilling stress among clones of a tropical tree, Hevea brasiliensis
Contrasting strategies to cope with chilling stress among clones of a tropical tree, Hevea brasiliensis
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DOI：
10.1093/treephys/tpq075
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发表时间：
2010-11-01
期刊：
影响因子：
4
通讯作者：
Roeckel-Drevet, Patricia
中科院分区：
文献类型：
--
作者：
Mai, Jing;Herbette, Stephane;Roeckel-Drevet, Patricia
八橡胶树Muell。精氨酸。比较克隆（GT1、YUNYAN77-4、IRCA707、IRCA317、PB217、PB260、PR107 和 RRIM600）对冷胁迫的耐受性。净光合作用 (Pn)、气孔导度 (Gs)、最佳有效光化学效率（F-v/F-m 和 F'(v) = F'(m)）、非光化学猝灭、细胞裂解和叶片坏死在 10 摄氏度冷冻 96 小时以及在 28 摄氏度恢复后进行测量。此外，抗坏血酸过氧化物酶、过氧化氢酶、脱氢抗坏血酸监测还原酶、谷胱甘肽还原酶、单脱氢抗坏血酸还原酶和超氧化物歧化酶活性。克隆 RRIM600 似乎是最具耐受性的，因为它没有表现出细胞裂解或叶坏死，并且如 Pn、Gs、Fv/Fm 和 F'(v) = F'(m) 所示恢复得最好。它维持寒冷胁迫的能力似乎部分与气孔的快速关闭有关，这表明该克隆有一种“回避策略”。 IRCA707、GT1 和 YUNYAN77-4 也对冷处理具有耐受性，仅观察到少量叶片损伤。然而，YUNYAN77-4表现出特殊的行为，在低温的第一小时内气孔张开较大，在10℃下96小时后有一定的光合活性，但Pn恢复最慢。在 PB260、IRCA317、PR107 和 PB217 克隆上观察到最大的细胞或叶子损伤，因此被分类为对寒冷敏感。这些克隆表现出 Pn、F-v/F-m 和 F'(v) = F'(m) 的最强下降，而 F-v/F-m 和 F'(v) = F'(m) 的恢复最慢，表明光系统 II 对低温具有高度敏感性。在冷却动力学过程中，观察到所有克隆的各种酶活性及时增加。在恢复过程中，在最耐受的克隆中观察到酶活性的最强增加，这表明有效的活性氧消除是确定橡胶树耐冷性的关键步骤，尽管涉及的酶因不同的耐受性克隆而异。这项研究指出了橡胶树克隆在应对寒冷压力和恢复方面的对比策略。
Eight Hevea brasiliensis Muell. Arg. clones (GT1, YUNYAN77-4, IRCA707, IRCA317, PB217, PB260, PR107 and RRIM600) were compared for their tolerance towards chilling stress. Net photosynthesis (Pn), stomatal conductance (Gs), optimal and effective photochemical efficiencies (F-v/F-m and F'(v) = F'(m)), non-photochemical quenching, cellular lysis and leaf necrosis were measured on trees chilled at 10 degrees C for 96 h, as well as upon recovery at 28 degrees C. In addition, ascorbate peroxidase, catalase, dehydroascorbate reductase, glutathione reductase, monodehydroascorbate reductase and superoxide dismutase activities were monitored. Clone RRIM600 appeared to be the most tolerant, because it showed no cellular lysis or leaf necrosis and the best recovery as revealed by Pn, Gs, Fv/Fm and F'(v) = F'(m). Its ability to sustain chilling stress seemed related in part to the fast closure of stomata, suggesting an 'avoidance strategy' for this clone. IRCA707, GT1 and YUNYAN77-4 were also tolerant to the cold treatment as only a few leaf injuries were observed. However, YUNYAN77-4 showed a particular behaviour with a large stomata opening during the first hour of chilling, some photosynthetic activity after 96 h at 10 degrees C, but the slowest recovery in Pn. The greatest cell or leaf damage was observed on PB260, IRCA317, PR107 and PB217 clones, thus classified as sensitive to chilling. These clones showed the strongest decrease in Pn, F-v/F-m and F'(v) = F'(m) and the slowest recovery for F-v/F-m and F'(v) = F'(m), indicating a high sensitivity of photosystem II to cold temperatures. Punctual increases of various enzymatic activities were observed for all clones during chilling kinetics. During recovery, the strongest increases in enzymatic activity were observed for the most tolerant clones, suggesting that efficient reactive oxygen species elimination is a crucial step for determining chilling tolerance in Hevea although the enzymes implicated varied from one tolerant clone to another. This study points out contrasted strategies of the Hevea clones in copping with chilling stress and recovery.