The vasculature provides multicellular organisms with transport routes for nutrients and signalling molecules, and in plant leaves this vital function is provided by the veins. Vein patterning is known to be regulated by the hormone auxin and the auxin transporter PIN1, but it has been unclear where in the leaf PIN1 needs to transport auxin for the hormone to pattern veins. Although the prevailing notion has been that epidermal peaks of PIN1 expression lead to localised transport of auxin into the inner tissues, thereby promoting vein formation, this hypothesis had yet to be tested. Now, Enrico Scarpella and colleagues instead find that epidermal PIN1 expression is dispensable for vein development. When PIN1 is expressed exclusively in inner or vascular tissues, the abnormal vein pattern of pin1 mutants is rescued; by contrast, PIN1 expression in the epidermis or non-vascular inner tissues fails to rescue the mutant pattern. These effects cannot be accounted for by compensation by PIN3, PIN4 and PIN7, even though they are expressed in the epidermis and inner tissues during vein patterning. Therefore, auxin transport in inner tissues, rather than the epidermis, is both required and sufficient for vein patterning.
PINning down plant vein patterning
PINning down plant vein patterning. Development 1 July 2020; 147 (13): e1302. doi:
Download citation file:
Advertisement
Cited by
Biologists @ 100 - join us in Liverpool in March 2025

We are excited to invite you to a unique scientific conference, celebrating the 100-year anniversary of The Company of Biologists, and bringing together our different communities. The conference will incorporate the Spring Meetings of the BSCB and the BSDB, the JEB Symposium Sensory Perception in a Changing World and a DMM programme on antimicrobial resistance. Find out more and register by 28 February 2025 to join us in March 2025 in Liverpool, UK.
Call for papers – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues

Development invites you to submit your latest research to our upcoming special issue – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues. This issue will be coordinated by Guest Editors Meritxell Huch (Max Planck Institute of Molecular Cell Biology and Genetics, Germany) and Mansi Srivastava (Harvard University and Museum of Comparative Zoology, USA), working alongside our team of academic Editors. Submit your articles by 15 May 2025.
A case for broadening our view of mechanism in developmental biology

In this Perspective, B. Duygu Özpolat and colleagues survey researchers on their views on what it takes to infer mechanism in developmental biology. They examine what factors shape our idea of what we mean by ‘mechanism’ and suggest a path forward that embraces a broad outlook on the diversity of studies that advance knowledge in our field.
In preprints
Did you know that Development publishes perspectives on recent preprints? These articles help our readers navigate the ever-growing preprint literature. We welcome proposals for ‘In preprints’ articles, so please do get in touch if you’d like to contribute.