植物根部图解，显示了细胞和根毛分布，植物生长素（auxin）传输方向用粉红色标明。
（图片来源：Claire Grierson）
面对气候变化，由于肥料和供水导致了极大的能源和环境成本，让作物更有效率地吸收营养和水从而增加产量显得越发重要。英国布里斯托大学科学家揭示了如何增加植物根毛（root hair）长度，而具较长根毛的植物能更有效地吸收水和养分，从而可能提高作物产量。研究相关论文在线发表于12月14日的《自然—细胞生物学》（Nature Cell Biology）。
论文第一作者、布里斯托大学生物学博士生Angharad (Harry) Jones表示：“每根根毛都是一个单独的伸长的细胞，其长度依赖于植物生长激素的供给程度。难点在于理解植物生长素如何传送到根毛来促进生长。”1880年，达尔文和他的儿子Francis第一次发现了植物的向光性生长，这一发现最后导致了植物激素的发现。
由于无法直接观察到植物生长素，Jones使用了由美国巴德学院（Bard College）物理学家Eric Kramer创建的计算机模型来计算植物生长素可能会出现的位置。
模型揭示出了令人惊奇的结果，植物生长素不是直接到达根毛细胞，而是通过旁边的细胞作为管道来传输。在传输过程中，一些植物生长素发生泄露，为根毛细胞提供了令其生长的信号。这一新的见解将非常有助于农民培育可持续性作物，而且可降低肥料浪费，从而避免对生态系统造成严重破坏。
论文通讯作者、布里斯托大学的Claire Grierson补充说：“这一重要的新工作是‘综合生物学’的一个例子， 是一种创新的、多学科方法，利用数学模型和计算机模拟来验证单靠实验很难或无法研究的想法。这一方法产生了对生物学机理突破性和令人惊奇的理解，而用其它方法很可能无法发现。”（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Cell Biology，doi:10.1038/ncb1815，Angharad R. Jones，Claire S. Grierson
Auxin transport through non-hair cells sustains root-hair development
Angharad R. Jones1, Eric M. Kramer2,3, Kirsten Knox4,5, Ranjan Swarup3,6, Malcolm J. Bennett3,6, Colin M. Lazarus1, H. M. Ottoline Leyser4 & Claire S. Grierson1
The plant hormone auxin controls root epidermal cell development in a concentration-dependent manner1, 2, 3. Root hairs are produced on a subset of epidermal cells as they increase in distance from the root tip. Auxin is required for their initiation4, 5, 6, 7 and continued growth8, 9, 10, 11, but little is known about its distribution in this region of the root. Contrary to the expectation that hair cells might require active auxin influx to ensure auxin supply, we did not detect the auxin-influx transporter AUX1 in root-hair cells. A high level of AUX1 expression was detected in adjacent non-hair cell files. Non-hair cells were necessary to achieve wild-type root-hair length, although an auxin response was not required in these cells. Three-dimensional modelling of auxin flow in the root tip suggests that AUX1-dependent transport through non-hair cells maintains an auxin supply to developing hair cells as they increase in distance from the root tip, and sustains root-hair outgrowth. Experimental data support the hypothesis that instead of moving uniformly though the epidermal cell layer3, 12, auxin is mainly transported through canals that extend longitudinally into the tissue.
1 School of Biological Sciences, University of Bristol, BS8 1UG, UK.
2 Physics Department, Bard College at Simon's Rock, Massachusetts, MA 01230, USA.
3 Centre for Plant Integrative Biology, University of Nottingham, LE12 5RD UK.
4 Department of Biology, University of York, YO10 5YW, UK.
5 Institute of Molecular Plant Sciences, University of Edinburgh, EH9 3JR, UK.
6 Plant Sciences Division, School of Biosciences, University of Nottingham, LE12 5RD UK.
