Differential contributions of ribosomal protein genes to Arabidopsis thaliana leaf development
Differential contributions of ribosomal protein genes to Arabidopsis thaliana leaf development
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DOI：
10.1111/j.1365-313x.2010.04457.x
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发表时间：
2011-03-01
期刊：
影响因子：
7.2
通讯作者：
Tsukaya, Hirokazu
中科院分区：
文献类型：
--
作者：
Horiguchi, Gorou;Molla-Morales, Almudena;Tsukaya, Hirokazu
在拟南芥中，编码核糖体蛋白（r蛋白）的基因突变扰乱了各种发育过程。这些扰动是由总体核糖体不足引起的还是由特定核糖体蛋白质缺乏引起的核糖体部分功能障碍引起的尚不清楚。为了区分这些可能性，需要使用几种r蛋白突变体进行比较研究。在这里，我们确定了11个r-蛋白基因的突变，从以前分离的齿状和尖叶突变体。这些突变大多与尖叶有关，由于栅栏叶肉细胞和铺面细胞的数量或大小减少而导致生长减少。此外，叶片离轴化通常观察到这些r-蛋白突变相结合的不对称leping 1（as 1）和as 2突变。这些结果表明，叶极性的建立是高度敏感的核糖体功能一般。然而，一些r-蛋白突变体表现出对特定发育缺陷的偏好。例如，rp 14 d突变不影响细胞增殖，但在as 1和as 2背景下引起叶片的强烈离轴化。另一方面，rps 28 b增强as 2叶片离轴化的程度比预期的弱，基于其对细胞增殖的负面影响。此外，亚纯型rps 6a等位基因有最强的影响，对大多数的表型检查。这些发现表明，这三种r蛋白基因的缺陷导致核糖体功能障碍。根据它们的结构异常，功能障碍的核糖体可能会影响参与调节某些叶发育过程的特定转录本的翻译。
P>In Arabidopsis thaliana, mutations in genes encoding ribosomal proteins (r-proteins) perturb various developmental processes. Whether these perturbations are caused by overall ribosome insufficiency or partial dysfunction of the ribosome caused by deficiency of a particular ribosomal protein is not known. To distinguish these possibilities, a comparative study using several r-protein mutants was required. Here, we identified mutations in 11 r-protein genes from previously isolated denticulata and pointed-leaves mutants. Most of these mutations were associated with pointed leaves, with reduced growth due to a decrease in the number or size of palisade mesophyll and pavement cells. In addition, leaf abaxialization was usually observed when these r-protein mutations were combined with asymmetric leaves1 (as1) and as2 mutations. These results suggest that the establishment of leaf polarity is highly sensitive to ribosome functionality in general. However, several r-protein mutants showed a preference towards a specific developmental defect. For example, rpl4d mutations did not affect cell proliferation but caused strong abaxialization of leaves in the as1 and as2 backgrounds. On the other hand, rps28b enhanced leaf abaxialization of as2 to a weaker extent than expected on the basis of its negative effect on cell proliferation. In addition, hypomorphic rps6a alleles had the strongest effects on most of the phenotypes examined. These findings suggest that deficiencies in these three r-protein genes lead to production of dysfunctional ribosomes. Depending on their structural abnormalities, dysfunctional ribosomes may affect translation of specific transcripts involved in the regulation of some leaf developmental processes.