Silencing of chaperonin 21, that was differentially expressed in inflorescence of seedless and seeded grapes, promoted seed abortion in tobacco and tomato fruits

Abstract

Vitis vinifera L. cv. 'Thompson Seedless' presents a type of stenospermocarpy in grape where fertilization occurs but seeds abort and fail to develop. To unravel the molecular basis for stenospermocarpy in grapes, subtractive hybridization was carried out in order to isolate differentially regulated genes that participate in the seedlessness machinery. Two 'Thompson' lines, a seeded and a seedless, were screened during different flower developmental stages. One of the genes, that was differentially expressed between the seeded and seedless lines, was the chloroplast chaperonin 21 (ch-Cpn21). ch-Cpn21 is a 21-kDa co-chaperonin polypeptide formed by two GroES-like domains fused together in tandem. Silencing of ch-Cpn21 in Nicotiana benthamiana plants resulted in leaf stunting, chlorosis, as well as ovary necrogenesis leading to seed abortion. Moreover, organ-specific silencing of ch-Cpn21 only in Lycopersicum esculentum fruits resulted in the development of seedless tomatoes. These results suggest that ch-Cpn21 may play a role in seed abortion in stenospermocarpic grapes.

CHAPERONIN 20 mediates iron superoxide dismutase (FeSOD) activity independent of its co‐chaperonin role in Arabidopsis chloroplasts

“…Therefore, the decreased CPN20 level was accompanied by reduced FeSOD activity in vivo . The VIGS plants also showed similar results (Hanania et al ., ), with a pale‐green phenotype (Fig. S9).…”

Cpn20: Siamese twins of the chaperonin world

“…Silencing of this gene in Nicotiana benthamiana led to a chain of pathologies resulting in seed abortion. In the same study, tomatoes into which Tobacco Rattle Virus containing cpn20 antisense was directly injected also failed to develop seeds, implicating cpn20 in seed development of Lycopersicon esculentum as well (Hanania et al 2007). …”

Virus-Based MicroRNA Silencing in Plants

“…Besides the aerial parts such as leaf and flower, TRVbased vectors are able to trigger VIGS in fruits (Hanania et al, 2007;Jia et al, 2011) and underground tissues (Valentine et al, 2004;Kaloshian, 2007) in various plant species. On the other hand, TRV-based vectors have been used to express foreign genes in systemically infected leaves (MacFarlane and Popovich, 2000) and in hairy roots (Larsen and Curtis, 2012).…”