Monihan Shea M, Magness Courtney A, Yadegari Ramin, Smith Steven E, Schumaker Karen S
School of Plant Sciences (S.M.M., C.A.M., R.Y., K.S.S.) and School of Natural Resources and the Environment (S.E.S.), University of Arizona, Tucson, Arizona 85721.
School of Plant Sciences (S.M.M., C.A.M., R.Y., K.S.S.) and School of Natural Resources and the Environment (S.E.S.), University of Arizona, Tucson, Arizona 85721
Plant Physiol. 2016 May;171(1):369-79. doi: 10.1104/pp.16.00334. Epub 2016 Mar 15.
The accumulation of sodium in soil (saline conditions) negatively affects plant growth and development. The Salt Overly Sensitive (SOS) pathway in Arabidopsis (Arabidopsis thaliana) functions to remove sodium from the cytosol during vegetative development preventing its accumulation to toxic levels. In this pathway, the SOS3 and CALCINEURIN B-LIKE10 (CBL10) calcium sensors interact with the SOS2 protein kinase to activate sodium/proton exchange at the plasma membrane (SOS1) or vacuolar membrane. To determine if the same pathway functions during reproductive development in response to salt, fertility was analyzed in wild type and the SOS pathway mutants grown in saline conditions. In response to salt, CBL10 functions early in reproductive development before fertilization, while SOS1 functions mostly after fertilization when seed development begins. Neither SOS2 nor SOS3 function in reproductive development in response to salt. Loss of CBL10 function resulted in reduced anther dehiscence, shortened stamen filaments, and aborted pollen development. In addition, cbl10 mutant pistils could not sustain the growth of wild-type pollen tubes. These results suggest that CBL10 is critical for reproductive development in the presence of salt and that it functions in different pathways during vegetative and reproductive development.
土壤中钠的积累（盐渍条件）会对植物的生长发育产生负面影响。拟南芥中的盐过度敏感（SOS）途径在营养发育过程中发挥作用，将细胞质中的钠去除，防止其积累到有毒水平。在该途径中，SOS3和类钙调神经磷酸酶B10（CBL10）钙传感器与SOS2蛋白激酶相互作用，以激活质膜（SOS1）或液泡膜上的钠/质子交换。为了确定在生殖发育过程中响应盐胁迫时相同的途径是否起作用，对在盐渍条件下生长的野生型和SOS途径突变体的育性进行了分析。响应盐胁迫时，CBL10在受精前的生殖发育早期起作用，而SOS1主要在受精后种子发育开始时起作用。SOS2和SOS3在响应盐胁迫的生殖发育中均不起作用。CBL10功能丧失导致花药开裂减少、雄蕊花丝缩短和花粉发育异常。此外，cbl10突变体雌蕊无法维持野生型花粉管的生长。这些结果表明，CBL10在盐胁迫存在的情况下对生殖发育至关重要，并且它在营养发育和生殖发育过程中发挥不同的途径作用。
