Legume plants may facilitate Zanthoxylum bungeanum tolerance to extreme rainfall

Zilong Li,Dagang Song,Kaiwen Pan,Xiaogang Wu,Xiaoming Sun,Lin Zhang,Feng Sun,Sizhong Wang,Akash Tariq

doi:10.1038/s41598-018-34449-w

Abstract

A complete randomized design was implemented with two watering regimes (extreme rainfall and control) and three different plant combinations (Zanthoxylum bungeanum, Z. bungeanum + Capsicum annum, Z. bungeanum + Glycine max) in order to assess the morphological and physio-biochemical responses of focal and neighbor plants. The results indicated that, extreme rainfall had significantly negative impacts on Z. bungeanum in three intercropping systems. However, intercropping with G. max improved the transpiration rate (Tr) and stomatal conductance (Gs), raised leaf relative water content (LRWC), increased chlorophyll a (Chl a) and carotenoid (Car) content, and enhanced the superoxide dismutase activity (SOD) of Z. bungeanum. After recovery, the Z. bungeanum + G. max mixed culture significantly increased soil NO3−-N, improved the intercellular carbon dioxide concentration (Ci) and Tr, upregulated soluble sugar and proline, and enhanced hydrogen peroxidase activity (CAT). Moreover, the higher root biomass of G. max provided much more nitrogen for Z. bungeanum via the return of organic matter. However, intercropping with C. annum significantly increased active oxygen (ROS). Compared with neighboring species, in intercropping systems, G. max could have improved the tolerance of the focal species Z. bungeanum in response to extreme rainfall and its recovery after extreme rainfall.

Highlights

Since the late 19th century, the global average surface temperature has increased by 0.85 (0.65–1.06)°C and is predicted to show a continuous warming of >1.5 °C by the end of the century[1]
Our results indicated that extreme rainfall did not significantly decreased the leaf relative water content (LRWC) and height of Z. bungeanum in a legume mixed culture (G. max.), and it reduced the height of Z. bungeanum in the nonleguminous mixed culture (C. annuum) (Table 3)
The present study shows that the chlorophyll a (Chl a), Chl b and Car content of the focal species in the Z. bungeanum + G. max (Z-G) mixed culture increased significantly under extreme rainfall

Summary

Introduction

Since the late 19th century, the global average surface temperature has increased by 0.85 (0.65–1.06)°C and is predicted to show a continuous warming of >1.5 °C by the end of the century[1]. It is well known that community composition influences plant responses to climate change, with plant-plant interactions playing a key role[11,12,13]. While they are still not well understood, competition and facilitation are expected to mediate the effects of extreme rainfall[14,15,16]. The fruits of Z. bungeanum are medicinal raw materials used for the treatments of toothache and rheumatism and are an important flavoring in Chinese food[26]. It is drought resistant and grows quickly. Due to its important functions, researches into Z. bungeanum has gained increased attention from scientists[27]

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Discussion

Conclusion