作為植物葉子表皮組織與大氣之間交換二氧化碳的門戶,，氣孔是植物生理中的關(guān)鍵要素,。因此，它們也是植物的遺傳及環(huán)境調(diào)控的焦點(diǎn),，但此前一直沒(méi)有發(fā)現(xiàn)氣孔發(fā)育的正信號(hào)作用因子?，F(xiàn)在，一種具有氣孔誘導(dǎo)性質(zhì)的蛋白已在擬南芥中被發(fā)現(xiàn),。
該蛋白被稱為“氣孔蛋白”（Stomagen）,，它是一種富含半胱氨酸的肽，見(jiàn)于新葉子內(nèi)組織（葉肉）層中,，在那里它可能通過(guò)與細(xì)胞表面受體TMM結(jié)合來(lái)起動(dòng)氣孔細(xì)胞系的形成,。這一發(fā)現(xiàn)提出一個(gè)可能性：“氣孔蛋白”也許可用來(lái)培育具有高氣孔密度、從而具有高二氧化碳吸收容量的作物和樹(shù)木——不僅可以通過(guò)基因工程方法來(lái)培育,，而且可通過(guò)噴灑合成“氣孔蛋白”或相關(guān)合成肽的方法來(lái)培育,。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 463, 241-244 (14 January 2010) | doi:10.1038/nature08682
Stomagen positively regulates stomatal density in Arabidopsis
Shigeo S. Sugano1,4, Tomoo Shimada1,4, Yu Imai1, Katsuya Okawa2, Atsushi Tamai3, Masashi Mori3 & Ikuko Hara-Nishimura1
1 Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
2 Innovative Drug Research Laboratories, Kyowa Hakko Kirin Co., Ltd., Taksasaki 370-1295, Japan
3 Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi-machi, Ishikawa 921-8836, Japan
4 These authors contributed equally to this work.
5 Correspondence to: Ikuko Hara-Nishimura1 Correspondence and requests for materials should be addressed to I.H.-N.
Stomata in the epidermal tissues of leaves are valves through which passes CO2, and as such they influence the global carbon cycle1. The two-dimensional pattern and density of stomata in the leaf epidermis are genetically and environmentally regulated to optimize gas exchange2. Two putative intercellular signalling factors, EPF1 and EPF2, function as negative regulators of stomatal development in Arabidopsis, possibly by interacting with the receptor-like protein TMM3, 4, 5, 6. One or more positive intercellular signalling factors are assumed to be involved in stomatal development, but their identities are unknown7. Here we show that a novel secretory peptide, which we designate as stomagen, is a positive intercellular signalling factor that is conserved among vascular plants. Stomagen is a 45-amino--rich peptide that is generated from a 102-amino-acid precursor protein designated as STOMAGEN. Both an in planta analysis and a semi-in-vitro analysis with recombinant and chemically synthesized stomagen peptides showed that stomagen has stomata-inducing activity in a dose-dependent manner. A genetic analysis showed that TMM is epistatic to STOMAGEN (At4g12970), suggesting that stomatal development is finely regulated by competitive binding of positive and negative regulators to the same receptor. Notably, STOMAGEN is expressed in inner tissues (the mesophyll) of immature leaves but not in the epidermal tissues where stomata develop. This study provides evidence of a mesophyll-derived positive regulator of stomatal density. Our findings provide a conceptual advancement in understanding stomatal development: inner photosynthetic tissues optimize their function by regulating stomatal density in the epidermis for efficient uptake of CO2.
